Tyler Clippard was a late addition to the National League all-star roster, but that doesn’t overshadow what he’s accomplished for the Nationals. (Jonathan Newton/The Washington Post)

In the summer of 2011, Tyler Clippard gazed around the National League’s all-star clubhouse, and the moment staggered him. Eating lunch with Tim Lincecum and Matt Cain, Clippard felt more like a fan than a peer. The players in the room him would be his teammates for one game, but they existed on another plane. He was a setup reliever. They were superstars. He thought, “What am I doing here?”

Monday afternoon, Clippard took his seat at a podium, his name and the Washington Nationals’ logo on a placard behind him, surrounded again by the best baseball players in the world. The awe he felt three years earlier had vanished. When he looked around, he saw opponents who he knew respected him as one of them. He was still a setup reliever. But he belonged.

Tuesday night, Clippard will stand on the third base line at Target Field and listen to his name over the loudspeakers at the All-Star Game for the second time in four years. Clippard landed on the team as a last-minute replacement, a technicality that does not change what he’s done for a half decade.

In baseball’s most volatile profession, Clippard has been a constant. Relievers burn out like cheap neon lights. Last July, setup men Steve Delabar, Edward Mujica and Jesse Crain cracked all-star rosters. This year, Delebar’s ERA is 4.91, Mujica’s is 5.45 and Crain hasn’t thrown a pitch, beset by injury. No setup man since Justin Duchscherer in 2008 made two all-star teams before Clippard this year.

“Guys that are in my position, my role, he’s the person that you look at,” Pirates left-hander Tony Watson said.

Setup men, by trade, are neither consistent nor durable. Clippard is both. Since 2010, he has thrown 363 innings, more than any reliever in baseball; only Colorado Rockies right-hander Matt Belisle comes within 40 innings. Over that span, which included a 32-save cameo as closer in 2012, Clippard has struck out 10.56 hitters per nine innings with a 2.65 ERA.

“He’s done it for a long time,” Giants all-star outfielder Hunter Pence said. “That’s definitely undervalued. To stay healthy, that doesn’t happen by luck or by accident. You have to have a lot of respect for that. I don’t think that gets as much credit as it should — the volume of what he’s done, the consistency, the amount of years.”

Every time Clippard pitches, by the nature of his job, the consequences of failure could be catastrophic. In April, after two ragged weeks, he blew an eighth-inning lead at Nationals Park. As he walked off the mound, four years of excellence paled to four innings of struggle. He heard boos rain from the seats. “Okay,” he thought. “All right.” The attrition of his position, no matter how well he established himself, never strays far from his mind.

“It’s a big motivating factor for me,” Clippard said. “I know how volatile the position can be. As soon as you have one bad season, they’ll turn the page on you and move to the next guy. As many times as I’ll have a great year, the expectations are even higher to have the same year again. So it motivates me to stay at that level, or even progress. There’s really not a lot of room for error. That’s been a big key for me, having that fire underneath me. Nothing is given. No matter how many years I’ve done it in a row, it’s not given.”

In the face of consistent success, Clippard has pushed himself to improve and adapt. This year, Clippard is striking out more hitters (11.93 per nine innings), yielding fewer home runs (0.45 per nine innings) and inducing more groundballs (38.7 percent of at-bats) than at any point in his career.

“You can’t be afraid to make changes,” he said. Clippard conceded his trademark high fastball no longer worked like it once did. Hitters had grown accustomed to it, and his execution of the pitch worsened. He made subtle changes. He throws more splitters, which have produced more swing-and-miss and strikeouts. He works down in the zone with his fastball, which leads to more grounders and fewer homers. It also means more hits, and the seven he has allowed per nine innings is a career high. But Clippard understands the give-and-take — more base runners, less instant damage — and lives with it.

Clippard’s cartoon change-up and deceptive fastball — “the Invisiball,” Nationals reliever Drew Storen calls it — have remained the centerpiece of his attack. In 2011, he threw cutters as a change of pace. In 2012, he leaned on a curveball more often. Late last season, Clippard integrated a splitter into his arsenal. It has become perhaps his nastiest pitch, what he goes to with two strikes.

The splitter had made it into the Rockies’ scouting report by the time they came to Washington in June, so Troy Tulowitzki knew Clippard might throw him one. On an 0-2 count, Clippard rifled one at him. The ball tumbled into the dirt at 86 mph, and Tulowitzki corkscrewed as he whiffed for strike three.

“To get a chance to see it when he struck me out on it, I think it put him on another level,” Tulowitzki said. “I tip my cap to him, because a lot of pitchers remain the same guy. I think he’s really changed it up. He was already good, but now he’s even better. . . . You can’t stay the same guy in this league, or they catch up to you. He’s evolved.”

Clippard also struck out Miami Marlins slugger Giancarlo Stanton with the splitter early in the year. Still, Clippard’s change-up stuck in Stanton’s mind as his most devastating pitch. Pence called facing Clippard a “mind game.” He never knows what he will see, partly because of Clippard’s hidden advantage. His large hands allow him to change pitch grips easily, so he does not tip his pitches.

“You have to have a very specific approach to him when you face him,” Stanton said. “You’re most likely going to see a change-up. It’s either going to be in the dirt, or he’s going to leave it up. But if he leaves it up, he’s so good at the arm action, sometimes you can still be out in front.”

Clippard remains a setup man, in part, because the Nationals have not allowed him to work the ninth inning. “Maybe if he went somewhere else, he could be the closer,” Cardinals all-star setup reliever Pat Neshek said. “Everybody knows that, I think.”

He wants to close, and he already has proved he can handle the job. But for now he will remain the standard at a position that rarely breeds standard bearers. When Clippard looked around the room Monday afternoon, he saw equals. He had become one of those players who awed him years earlier, a player other all-stars see and know they have arrived.

Watson had never met Clippard, but he had wondered how he had done what he does so well for so long. “I’m going to ask him here for sure,” Watson said.