Adam Eaton scores the first run at Nationals Park of the 2018 season. Eaton was pulled from the game in the sixth inning. (Jonathan Newton/The Washington Post)

The news was promptly announced at 7 a.m. Thursday. The Washington Nationals and General Manager Mike Rizzo had agreed to a two-year contract extension, ensuring that the architect of one of baseball’s model franchises is sticking around through at least the 2020 season. A few hours later, as Nationals Park filled with frigid fans eager to watch the championship-contending club Rizzo has built for the first time in 2018, positive vibes reverberated. Smiles were everywhere. It was a good morning for the Nationals organization.

But by the end of the afternoon, after Stephen Strasburg’s laboring and Adam Eaton’s ominous early exit, after Trea Turner was ejected and Brandon Kintzler gave up a grand slam, a hush enveloped the 10-year-old ballpark. For the third straight day, the Nationals were humbled by a supposedly inferior National League East rival in an 8-2 loss against the New York Mets.

After beginning the season on a four-game winning streak, the Nationals are 4-3 a week into the season. The Mets, their presumed top divisional competition, improved to 5-1. The three-game losing streak was met with shrugs.

“I’d rather be playing good in October and September than in April, to be honest with you,” Eaton said. “We’ve played good in April, and we’ve seen how that ended.”

Thursday’s chill was unforgiving. A biting breeze exacerbated it. The sun only helped so much. So it was a tad cruel that the typical pregame home opener spectacle featured longer-than-usual introductions for the home club. Each Nationals player’s introduction included a complementary biographical blurb, extending a ceremony further than most. The Mets, meanwhile, stood along the third base line, hands in their pockets, bouncing around to generate warmth. The thermometer read 42 degrees.

As that carried on (without the ritual flyover because President Trump’s impending travel made the area restricted airspace), Strasburg warmed in the bullpen, preparing to make his second start of the season. And after Winter Olympian Maame Biney and Winter Paralympic gold medalist Noah Grove walked the Nationals’ lineup card to home plate alongside Manager Dave Martinez, Strasburg took the mound to annihilate the top of the Mets lineup. He needed 11 pitches to retire the side. He struck out Michael Conforto on three fastballs to begin the inning. He got Yoenis Cespedes swinging at a change-up to end it.

The rest of his day, however, was strenuous. Working with a one-run lead after hits by Eaton and Anthony Rendon off right-hander Jacob deGrom and a Mets error, Strasburg watched Jay Bruce whack his first pitch for a double. Two batters later, he issued a four-pitch walk to Kevin Plawecki. Then, with the runners on the corners, he was called for a balk, and Bruce scored to tie the game. It was Strasburg’s first balk since 2013 and the fourth of his career.

“I don’t know what happened,” Strasburg said. “I was thinking step off and I just spun, and obviously when you don’t spin off you have to throw the ball. I was thinking step off.”

Eaton and Rendon combined to catapult the Nationals ahead again in the third inning. Eaton initiated the scoring with a two-out walk. Rendon, who entered the day 0 for 19 with six strikeouts in his career against deGrom, followed with a double to left field into the left-field corner. Third base coach Bob Henley, never afraid of sending a runner, waved Eaton home. A good relay would have gotten him in plenty of time, but the catcher bobbled the ball. Eaton, who tore his anterior cruciate ligament and severely sprained his left ankle last April, belly-flopped home to complete his sprint from first base.

Eaton appeared to survive the odd slide unscathed until Brian Goodwin replaced him before the start of the sixth inning. After the game, Eaton explained he “tweaked” the ankle on the slide and the club’s decision to remove him was precautionary. He maintained a stint on the disabled list won’t be necessary. Martinez said tests on the ankle were negative.

“A little scar tissue decided to come up during that [slide], they don’t think anything major,” Eaton said. “It’s like a day or so for it to realign itself and be good.”

That one-run edge, while nearly very costly, was definitely fleeting. In the fourth inning, Cespedes, a connoisseur of low-ball smashing, golfed a 95 mph fastball below his knees over the wall for a solo home run. An inning later, Conforto, making his season debut, cracked a 1-2 fastball the other way. The ball was originally called a double after bouncing just over the left-field wall and back onto the field. But the ruling was overturned upon replay review, giving Conforto a two-run home run and the Mets a 4-2 lead. Strasburg would grind through six innings, allowing the four runs on five hits and two walks. He threw 92 pitches.

“I know mistakes were made, and I paid the price for it,” Strasburg said. “Sometimes you get away with them. But this time I didn’t.”

Once again, the Nationals had to wait until the top of their order came up to challenge deGrom. After retiring seven straight, deGrom surrendered a leadoff single to Goodwin in the sixth. He then issued four-pitch walks to Rendon and Bryce Harper, loading the bases with no outs. A blow seemed imminent. The Nationals wound up with nothing. Ryan Zimmerman popped out, Howie Kendrick whacked a line drive right at the shortstop, and Turner struck out looking.

It was the third time Turner, bundled in a red balaclava, struck out on the day. It was the second time looking. Frustrated with the strikeout call on a pitch that appeared out of the strike zone, he shared a few of his thoughts with home plate umpire Doug Eddings. The disclosure provoked his first career ejection.

“I felt like that was a big spot in the game,” Turner said. “It kind of turned after that. Unfortunately, I had the bat taken out of my hands there.”

The stunning turn of events quieted the crowd. The dagger came next. Summoned from the bullpen to keep the deficit at two, Kintzler allowed a double to pinch hitter Brandon Nimmo. He then walked Conforto and Cespedes. That loaded the bases for Bruce, who fell behind 0-2 and took a borderline ball to run the count full before Kintzler threw a sinker over the heart of the plate. Bruce launched it. Kintzler didn’t bother to turn around as the towering flyball landed in the seats beyond the wall in right-center field for a grand slam. It was the first home run Kintzler has allowed this season. It blew the game open.

Fans soon exited in droves, disappointed with the first of 81 regular season contests scheduled on South Capitol Street this year. But Thursday was still, all told, a good day for the Nationals. The man who’s overseen the franchise’s turnaround and constructed playoff clubs in four of the past six years isn’t going anywhere anytime soon. It was cause for celebration. But it ended on a sour note they’ll have to wait until at least Saturday, after Friday’s day off, to sweeten. Not that the Nationals seem worried.

Red-hot Adam Eaton leaves game after dislodging scar tissue

After Adam Eaton reached base twice in two at-bats, scored twice in two at-bats and essentially sparked both Washington Nationals rallies in the first few innings of their home opener, he abruptly left the game in the top of the sixth inning. The trouble, he and his manager explained later, was in his left ankle. Scar tissue dislodged on an awkward slide in the third inning, and began causing discomfort. All tests, including X-rays, were negative. Neither Eaton nor Dave Martinez expects him to need time on the disabled list.

“I don’t know all the technical jazz that goes along with it, but I think a little tweak, a little scar tissue decided to come up during that [slide]. But they don’t think anything major,” Eaton said. “It’s like a day or so for it to realign itself and be good.”

The trouble occurred after Eaton walked to lead off the third inning. When Anthony Rendon doubled, third base coach Bob Henley waved Eaton home, an aggressive move that required him to make an awkward slide into home plate. Though he got there safely, he seemed to land awkwardly on his right arm before adjusting to get to the base. Eaton popped up and headed to the dugout. Later, he called the send “awesome,” and his manager had no problem with it.

“At that point, Adam’s not going to slow down. I mean, you know how he is. He’s rip-raring to go. He said he felt great,” Martinez said after the Nationals’ 8-2 loss to the New York Mets on Thursday. “At that point in the game, Bobby sent him. He tells Bobby every day how he feels, and he said he felt fine. He caught his spike or two when he slid.”

Read the full story here.

— Chelsea Janes

Reader Q&A with Adam Kilgore

The Post’s Adam Kilgore answered readers’ questions in the comments throughout Thursday’s game.

On the Eaton situation:

This is wildly jumping the gun, but we’re typing in the comments section during a baseball game, so why not? Should Eaton miss any time, even a minimum 10 days on the DL, the Nats would be well-positioned to replace him. Brian Goodwin is a serviceable everyday outfielder, and maybe better. If Eaton is out for a short period, the Nats may not want to bother starting the service time clock on uberprospect Victor Robles, who looked sharp in his cameo last fall. But Andrew Stevenson has MLB experience and a good glove.

It would be a big blow if Eaton serves time on the DL, but outfield is the spot where the Nats can best withstand such a detriment. And again, maybe Eaton will be in the lineup Saturday.

On Rizzo’s new deal:

If [Rizzo is] satisfied with it — and he is — that’s good enough for me. The Lerners don’t view contracts commensurate with the industry standard, which isn’t going to change now if it hasn’t already. So if the extension was going to happen, it was going to be like this. It’s important that it got done. Even Rizzo said he was worried about it becoming a distraction and had heard players wondering about it. The most significant ripple is that it means Rizzo will be the point person in negotiating any possible extension or free agent with Bryce Harper. That’ll get done (or not) ultimately at the ownership level, but Rizzo and Scott Boras speak the same language and know how to pull off a triangular negotiation with the Lerners.

On the balk, and what followed: “Strasburg’s response after balking in a run — a grounder from Jose Reyes — reminded how thoroughly he has quashed the narrative that he crumbles following adverse happenings.”

Rounding the bases

The Nats lost but hey, here’s some good news:

Before the game, Deputy First Class Blaine Gaskill, whose rapid response to a gunman at Great Mills High School last month helped bring the incident to an end, threw out the ceremonial first pitch.

Scott Allen posted updates from Nats Park on the @PostSports Instagram account. Follow his story.

For a full series preview, click here.

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Heading to a game soon? Here are a few things to know:

— Last month, the Nationals cut ties with Mike Isabella in the wake of news that the celebrity chef and four of his business partners were named in a sexual harassment lawsuit filed by a former top manager at his company. While the team was already planning to replace two of Isabella’s concession concepts — Kapnos at the Park and Catchfly — at Nationals Park this season, the allegations prompted the Nationals to also remove Isabella’s popular G sandwich stand. At Thursday’s home opener against the Mets, the Nationals debuted an entirely new concept in its place. Grace’s Kitchen, named after former first lady Grace Coolidge, will offer a rotating menu of items developed by local female business owners, chefs, and restaurateurs; the featured female partners and dishes will change throughout the season.

— What else is new inside Nationals Park? Try a revamped play area for kids, alcoholic juice boxes for adults and a variety of new hot dogs, for starters. Scott Allen has a full roundup of the additions to the ballpark. Outside the park, meanwhile, there are a few fresh places to pregame near the stadium, including Aslin Beer Garden and two pizza options, Declaration and All-Purpose Pizzeria. The beloved Bullpen bar and Bardo are back, as well.

— Let’s talk beer. The Nationals announced they will introduce 24- and 25-ounce large-format beer options throughout Nationals Park for the first time this season, but they didn’t offer much in the way of pricing information. A tweeted photo of a concession stand advertising craft draft beer for $16 led to people freaking out. Don’t freak out, writes Scott Allen.

— Gates opened at Nats Park at 11 a.m. (Here’s what you need to know about getting there this season.) There are a few changes to the park this year, including notable edits to the scoreboarda font tweak and the addition of a mound visit tracker.

Planning to watch games this year? That could be difficult if you’re a cord cutter.

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More reading:

Meet the Nationals’ new manager, Dave Martinez, who is making his players chill out. Martinez spent 10 seasons at the side of Joe Maddon, winning a World Series with the Cubs in 2016. In a profile of Martinez during the offseason, Chelsea Janes revealed that perhaps his best quality is connecting with players.

— Speaking of managers, Dave Sheinin caught up with ex-Nationals manager Dusty Baker last week, who told him, “You can make peace with [how Baker was let go in Washington], but it makes you kind of lose some faith in mankind.”

— On the field, this season is all about Bryce Harper. This might be the most scrutinized season of Harper’s career, as he approaches free agency. And yet … “I think the thing that surprises you is that while he embraces the spotlight he gets, it may not be what he wants. He just wants to play baseball,” Matt Wieters said.

The Nationals finallllllllllly have some bullpen stability. But even so, questions remain. “I want none of those guys getting hurt,” Martinez said. By the way, that bullpen features a closer with a big personality and a wife who is a star on social media. Sean Doolittle and Eireann Dolan may be baseball’s most woke couple.

— Notice anything missing on the Nationals this year? Possibly a hirsute outfielder? There’s a Jayson Werth-shaped hole in the Nationals clubhouse, but they’re filling the void by committee. Someone else who’s not here (though this guy could be soon): Victor Robles, the Nationals’ star of the future. Jorge Castillo spent time with Robles in his native Dominican Republic earlier this year and found a humble player with designs on being great.

Read our full season preview here.