Washington Nationals reliever Matt Grace delivers a pitch to the St. Louis Cardinals during the seventh inning Wednesday, his major league debut. (AP Photo/Nick Wass)

At 12:30 p.m. Wednesday, left-handed reliever Matt Grace was wearing a Syracuse Chiefs uniform, with no reason to expect he would be changing it anytime soon. The Chiefs had a home game against Rochester in about a half hour. Starter Taylor Hill was warming up in the bullpen. Grace was just about to head out there, too. It was almost time to settle in until the Nationals’ Class AAA affiliate needed a left-handed reliever with ground ball-getting stuff later that afternoon.

Then the Syracuse coaches called Grace in. They told the 26-year-old to get on a plane — and fast, because a 2:30 p.m. flight to Washington would be delivering him to the big leagues for the first time.

So Grace changed and rushed home, threw clothes in a bag, and headed to the Syracuse airport. He hustled through security in plenty of time to see his flight was delayed, late to arrive in Syracuse, then stalled by a mechanical issue. After four-plus seasons in the minors, Grace was being kept from the majors by a toilet that wouldn’t flush.

“It was a little added twist in the whole thing,” Grace said.

He arrived at Nationals Park about 20 minutes before Wednesday night’s game against the Cardinals started, pulled on the No. 60 jersey he wore all spring and headed to the bullpen. About two hours later, he made his major league debut with no time to consider the gravity of the moment.

“Which is probably a good thing,” Grace said afterward. “It was good to get in there. There wasn’t much time to really soak it all in. It was get here, and get in the game.”

Grace pitched a scoreless seventh against the Cardinals in the Nationals’ eventual 7-5 loss. His sinking fastball and slider combination induced ground balls as expected from the big-league club, first from red-hot Matt Carpenter, then from slugger Jason Heyward.

Nationals pitching coach Steve McCatty headed out to chat after Heyward grounded out, with right-handed batter Matt Holliday on deck. Grace had barely had time to pack his clothes, let alone look at scouting reports. But with another left-handed hitter behind Holliday, McCatty did not go out there to provide a Cliff Notes version of Holliday’s every tendency. Instead, he a simple directive: don’t give him anything to hit. Grace walked him. Matt Adams then grounded back to the mound for the final out of the inning. About nine hours after he shed his Chiefs jersey and hustled to the airport, Grace’s major league debut was complete — and scoreless, at that.

“It’s an adjustment, but it just boils down to executing pitches and really seeing the glove,” Grace said. “And if you can do that, it doesn’t really matter who’s at the plate. So I was trying to take that approach, really. Was just trying to see the glove and make a good pitch on each one.”

Grace impressed the Nationals in spring training with lots of movement that sometimes took uncommon trajectories. Nationals Manager Matt Williams said he saw some of Grace’s pitches mimic a right-hander’s movement on occasion. He gave up seven hits and three runs in 7 2/3 innings in Syracuse so far this season, striking out six.

The Nationals needed Grace, the third No. 2 left-handed reliever they have tried in the bullpen this season, because the second one was placed on the disabled list Wednesday retroactive to April 18. Young Felipe Rivero, called up from Class AA Harrisburg last week to join Matt Thornton and replace Xavier Cedeno, has a gastrointestinal bleed. The team would not provide more specific information than that.

“I think it’s a 15-day issue.” Williams said. “Without giving too much information because it’s doctor-patient privilege, it’ll be a short-term thing. He’ll be good to go.”

So for now, it’s Grace’s turn. He is the third reliever to make his major league debut for the Nationals this season, the 10th reliever to pitch overall. The Nationals used 12 relievers all of last season.

IN THE POST

The Nats came back against John Lackey Wednesday night, but fell to the Cardinals, 7-5.

IN THE JOURNAL

Danny Espinosa on how he’s improved his left-handed hitting.

Anthony Rendon will play with Harrisburg Friday, and will play third base for now.

Nationals call up Matt Grace, place Felipe Rivero on DL, trade Xavier Cedeno. 

NATIONALS MINOR LEAGUES

Rochester 11, Syracuse 7: Michael A. Taylor was 2 for 5 with a home run, Ian Stewart went 2 for 4 with a home run, and Jason Martinson homered, too — but Rochester outhit the Chiefs 16-8. Taylor Hill yielded six runs on eight hits in 3 2/3 innings, and Sam Runion allowed three earned runs in 1 2/3 innings.

Harrisburg: Postponed.

Wilmington 6, Potomac 3: The Blue Rocks roughed up Potomac starter Blake Schwartz for five runs on eight hits, then got a run off Tyler Mapes. Third baseman Drew Ward was 4 for 5 with a double and right fielder Brandon Miller homered for the P-Nats.

Delmarva 5, Hagerstown 4: Suns starter Luis Reyes kept Hagerstown in the game through five, allowing three runs on seven hits and striking out four. Catcher Matt Reistetter was 4 for 4 in the loss.