(Paul Sancya/AP)

Detwiler was not sure what he heard. His next start? Wasn’t he in the bullpen? He met with pitching coach Steve McCatty. “I guess Davey told you?” McCatty said to Detwiler. “I guess I did hear him right,” Detwiler thought. “What’s going on here?”

After waiting for five years, ever since the Nationals selected him with the sixth overall pick in 2007, Detwiler had been chosen for the Nationals rotation. He may not stick in the rotation long, with Chien-Ming Wang expected back within three or four weeks. But when Detwiler makes his first start tonight, he will be part of an opening day rotation for the first time.

“In the past, it’s been I’m coming up for somebody who’s hurt or I’m coming up for somebody who hasn’t been performing that well,” Detwiler said Sunday morning. “It’s kind of like they’re saying, ‘You’re our guy right now.’ It’s the first time I’ve really felt like that.”

This winter, and all through spring, Detwiler had a hard time seeing himself in the rotation. The Nationals overloaded their rotation this winter by signing Edwin Jackson and trading for Gio Gonzalez. Detwiler thought he had earned a spot at the end of last season, when in10 starts he punched up a 3.21 ERA. But when spring arrived, the Nationals sent Detwiler to the bullpen, and he wondered where he stood.

“All the signings they made, it was kind of, ‘What’s going to happen with me?’ ” Detwiler said. “Am I going to go somewhere else? Am I going to go to the ‘pen? What’s going to happen? I was talking with my agent. He just said, ‘You have no leverage. Just take it for whatever is going to happen. There’s no reason to fight it. You can’t do anything about it. Just go with it.’

“That kind of eased my mind. I just went with it. I was going to do whatever they told me to do, because they’re my employer. In the end, it worked out.”

Detwiler earned his spot. The easy choice would have been to keep John Lannan and his $5 million salary in the rotation, in the majors, and groom Detwiler out of the bullpen. But Detwiler pitched so well, blazing high, mid-90s fastballs and biting sliders, that the Nationals chose to give him a spot. He no longer needed any grooming.

The Nationals’ decision ended Detwiler’s long path to the rotation. He made his major league debut on the final day of the 2007 season, pitching an inning in an appearance stipulated by his draft contract. He made it back to the majors in 2009, making 14 starts not because he had developed, but because the Nationals had no one else.

“He battled some delivery issues early on,” General Manager Mike Rizzo said. “We rushed him to the big leagues right when we drafted him.”

By the start of 2010, Detwiler was ready to join the rotation. The Nationals reserved a place for him. But when he arrived at spring training, he felt pain in his right hip. He got it checked out, and doctors diagnosed a torn labrum. He needed surgery, and he missed half the season.

“I always look back on that,” Detwiler said. “What if I didn’t say anything? What if I just pitched through it?”

Detwiler reached the majors again in 2010, but he still felt the effects of his hip surgery into early last year. The Nationals still started him at Class AAA Syracuse. The strength came back in the middle of last year, but another change allowed Detwiler to take the final, most important step in his development.

It happened because of one pitch. Last May, Detwiler faced the Rochester Red Wings for the fourth time. His start unraveled from the start. He felt good about his pitches, every ball found a hole. He threw Toby Gardenhire – Detwiler remembers the name – an inside, 0-2 fastball at his eyes. He somehow got his barrel to the pitch and blooped it over the first baseman’s head.

“I was like, ‘What is going on here?’ ” Detwiler said. “I felt kind of defeated from that.”

After the Chiefs bused back to Syracuse, Manager Randy Knorr, now the Nationals’ bench coach, pulled Detwiler into his office. Knorr told him, in no uncertain terms, that Detwiler had looked defeated and needed to change his attitude.

“From the next start on, I kind of had a different demeanor about pitching,” Detwiler said. “Every pitch. It kind of molded it right there. Maybe two, three, four starts after that, I got called up. That was the one point I can always look back on to say, ‘This is when everything changed.’ I got the right demeanor and everything. I had a lot more confidence after that, too.”

Detwiler carried that with him. Tonight, he’ll take it to the mound in New York, a start that has been a long time coming.