The Nationals' Stephen Strasburg discussed the state of his arm, lessons learned from last season and what's to come for the Washington team during a break from spring training in Viera, Florida. (Whitney Leaming/The Washington Post)

The day after the longest game in team history, the weary Washington Nationals desperately needed a strong performance from Stephen Strasburg, the starter they have trusted with the ball on opening day three times. The team’s bullpen, the best in baseball, was so spent after logging so much work that the Nationals called up a 13th pitcher, a fresh arm from the minors, and rushed him to Miller Park in time for the game.

With a chance to sweep the Milwaukee Brewers, Strasburg instead faltered, and in his worst start of the season he tied his career high for runs allowed. The drained Nationals were thrashed, 9-2, by the Brewers on Wednesday. The Nationals should be happy about taking the series from the team with the best record in the National League, but the final game slipped through their fingers.

“Guys played great, so it kind of stings a little bit more,” Strasburg said. “I wanted to go out there and do my job and get the sweep. Just wasn’t able to get it done.”

The conditions for Strasburg seemed ideal. After an exhausting 16-inning game Tuesday, the Brewers rested three of their regulars: Aramis Ramirez, Ryan Braun and Jonathan Lucroy. Strasburg was opposed by Brewers right-hander Marco Estrada, who had allowed the most home runs (2.41 per nine innings) and had one of the worst ERAs (5.22) in baseball entering the game.

Perhaps the Nationals would score early runs against a struggling starter, and maybe Strasburg could hit a groove against a weakened lineup. The exact opposite occurred.

“Just wasn’t as pinpoint as he wanted to be,” Manager Matt Williams said. “We were limited, so we hoped he’d go further.”

Strasburg’s struggles started in the second inning. Mark Reynolds hit a low change-up for a single, and Elian Herrera added a one-out double on a fastball outside the strike zone. Strasburg then loaded the bases by walking the Brewers’ eight-hole hitter, Martin Maldonado, on seven pitches, none of them in the strike zone. Only four outs into the game, pitching coach Steve McCatty made a mound visit.

After a strikeout, all that stood between Strasburg and escaping the bases-loaded jam was leadoff hitter Scooter Gennett. Strasburg fell behind 2-1 on Gennett when he missed with two change-ups, the pitch he often uses to wriggle out of jams.

But with the count in the hitter’s favor, Strasburg needed a strike. He threw one, a fastball up in the strike zone and over the plate. Gennett crushed the ball to deep right-center field. Strasburg turned to see it clear the fence but quickly turned back to receive a new ball.

“You know, they’re a free-swinging team,” Strasburg said. “They’re going to run into balls. Missed my spot obviously, but kind of how it is right now.”

After the grand slam, Strasburg didn’t improve much. The Nationals trimmed the deficit to 4-2 in the fourth inning when Ian Desmond doubled to center field to score Ryan Zimmerman. But in the bottom of the inning, Strasburg allowed another home run, to Khris Davis. Strasburg threw a first-pitch fastball straight down the middle, and Davis flicked it over the left field fence.

The running theme with Strasburg’s bad starts is his command. After seven runs, eight hits and three walks Wednesday, Strasburg conceded he was lost. In his previous start, Strasburg allowed nine hits and four runs. Before that, he had a 2.15 ERA in his previous 10 starts.

“I’m not right mechanically right now, and I think it’s causing [hitters] to see the ball a lot better,” he said. “Happens to everybody. I’m going to keep working hard, and it’s going to turn.”

Asked about the root of the problems, Strasburg was terse: “Still trying to figure that out. Just doesn’t feel the same. Doesn’t look the same.”

In the fifth inning, Strasburg’s control worsened. With two outs, he gave up a triple to Carlos Gomez. He walked two straight batters with two outs. Davis then softly hit a fastball over the plate to right for a single, tacking on two more Brewers runs. Strasburg watched from the mound and didn’t back up a base.

“It’s hard to say” what the problem is, McCatty said. “Rushing a little bit, a little bit of collapsing on the back leg and a little lateral. Some of them looked like that. Something we’ll work on.”

The Brewers led 7-2 in the fifth, and Williams took Strasburg out. Only once before in his major league career had Strasburg allowed seven runs in a game. Two of the Brewers’ hits and two walks came with two strikes.

“The key for Stephen is going to continue to be to have fastball command early, be able to throw his breaking balls for strikes, use the change-up off of that,” Williams said. “[Wednesday] it was a little backwards.”

Rookie Taylor Hill, given the news of his call-up at 2 a.m. Wednesday, relieved Strasburg and allowed two runs over 31 / 3 innings. Hill, a starter in Class AAA Syracuse, settled in after a shaky sixth inning and finished the game in his major league debut.

“It was something I’ll never forget,” he said. “It was awesome.”

The Nationals rested Jayson Werth, Danny Espinosa and Jose Lobaton, and the lineup did little against Estrada. The Nationals scored two runs but managed only two hits and four walks against him.

“They had the same hours we did, and they came out swinging,” Williams said.

There was a minor skirmish in the eighth inning when Desmond took exception with Gomez’s take-out slide of Kevin Frandsen at second base. Gomez reached base when he was hit on the elbow with a pitch from Hill. On the next groundball, Gomez slid into Frandsen and past the bag. Desmond and Gomez exchanged words at the base, and the benches cleared.

“I didn’t agree with the way he slid into second base with a seven-run lead,” Desmond said. “I’ve defended that guy in a lot of clubhouse arguments. I respect the way he plays the game, but I got no respect for that.”

The crowd quickly dispersed, the game all but over. Three outs later, the Nationals and Strasburg packed up their belongings in a quiet clubhouse.