The removal of Stephen Strasburg from the Washington Nationals never seemed more real than Sunday afternoon, in the moments after Strasburg’s brilliance helped lift the team he will soon be separated from to a 4-3 victory over the St. Louis Cardinals. Manager Davey Johnson sighed and revealed the precise parameters, the unkind denouement to a decision made last year.

Strasburg will make two more starts. His final performance is on schedule for Sept. 12 at Citi Field against the New York Mets. The Nationals, owners of the best winning percentage in the major leagues and a 61 / 2-game lead in the National League East, have known for months their ace’s season would end in the thick of a playoff race. With September here and the fall chill approaching, they now know when.

Even with Washington’s first postseason baseball since 1933 in range, Nationals General Manager Mike Rizzo never felt a shred of regret about his decision to shut down Strasburg. He believes in his plan as staunchly now, with Strasburg sitting at 1561 / 3 innings, as he did when he made it, back before the first spring training ball had been thrown.

“There’s no doubt about it,” Rizzo said. “The plan was in place. It couldn’t have gone any better. He’s pitched extremely well. A couple more starts under his belt, it’ll really lay a solid foundation for 2013 for him. We’re going to take the ball and run with it and he’s going to win a lot of games for us.

“Just because we’re in a different position in the standings, we’re not going to forego my philosophy of player development and keeping pitchers healthy. We’re being consistent with it throughout.”

Strasburg all season has brushed off questions about his innings limit, which the Nationals prescribed for his first full season after Tommy John elbow reconstruction surgery. After he dominated the Cardinals, Strasburg continued to keep his thoughts to himself.

“I’m just focused on the next start,” Strasburg said. “That’s all I can really focus on right now. We’re going to have to have a sit-down and talk here soon. . . . I just don’t have anything to say. I’m in it with these guys, and we still got a long way to go. But I’m going to fight with them until the end.”

When the Nationals sit down and talk to Strasburg, it will be a one-way conversation. Teammates have assumed since last year Strasburg will be devastated. “They’re going to have to clean his locker out,” reliever Drew Storen said last month. “They’re going to have to take all his gloves away.” But Rizzo will not be swayed by Strasburg’s stance.

“I don’t think he’s going to fight me on it,” Rizzo said. “I know he’s going to be unhappy about it. He’s an ultimate competitor. But we’ve taken that out of his hands. This is a developmental decision. It ultimately falls on the doorstep of the general manager. And we’ve made it — made it five months ago. And we’re going to stick to it.”

Sunday afternoon, Strasburg showed why he his innings limit has created an unyielding controversy: because he is one of the most dominant forces in baseball. He bounced back from his worst start this season and shut out the Cardinals for six innings, striking out nine to bring his league-leading total to 195 and his ERA to 2.94, best in the rotation.

“He was coming out today and really establishing himself early and saying, ‘Here, I’m going to throw this ball down in the zone on both sides of the plate,’ ” said catcher Kurt Suzuki, who ripped a solo homer and an RBI single. “He was mixing in a few offspeed. You know, Stras being Stras.”

Rizzo and the Nationals have received mostly praise from the medical community, but mostly criticism from the baseball community. Another opinion came from the losing clubhouse Sunday.

“They’ve definitely got a great staff,” said Cardinals starter Adam Wainwright, who underwent Tommy John surgery in February 2011. “I just can’t get past that they’re shutting him down. What if he’s another Mark Prior? Mark Prior only had two to three good years, and he’s out of the game. It’s hard for me rationalize.”

Firstly, the Nationals are trying to avoid Strasburg becoming Prior. Secondly, Wainwright and Strasburg shared a surgery, but there is a crucial difference. Wainwright was 28 and had thrown 460 innings over the previous two seasons. Strasburg pitched only 44 innings last year, and at 24 he has yet to build enough arm strength to endure an entire season with high risk.

“This has been the protocol for two years now,” Nationals right fielder Jayson Werth said. “I mean, it’s real easy for people not in the organization and not on this team to point fingers and call people names, and say that this is what should happen and this is what shouldn’t happen. But the bottom line is, this is our guy on our team. And they’re doing what’s right for him and what’s right for our club long term. And I think it’s great.”

The rest of the Nationals’ clubhouse fell in line with Werth. They have gathered resolve from a season spent thriving despite injuries and their knowledge that, eventually, John Lannan would replace Strasburg in the starting rotation.

“In a perfect world, we all wish he could go,” said closer Tyler Clippard, who notched his 29th save on Sunday. “He’s a special talent, and you can’t that for granted, as much as you can’t take a season like this for granted. It’s a give-and-take, but the organization has to do what’s best for Stephen. I’m on board with that 100 percent. . . . We can win without him.”

They were forced to win Sunday after he left. Reliever Sean Burnett gave up a two-run, game-tying homer to Daniel Descalso in the seventh. The Nationals struck back immediately, roping four straight two-out hits in the bottom of the inning, capped by RBI singles by Ian Desmond and Danny Espinosa.

“That was huge,” Desmond said. “If we didn’t, they were going to. That was the way the whole series went — back and forth, back and forth. We just landed the last punch.”

The Nationals will soon be fighting with Strasburg shelved for the season. Without him, they still have one of the best rotations in baseball and a deep, currently scorching offense. They will still face the question: Can they win without Strasburg?

“Watch and see,” Desmond said.