JUPITER, Fla. • As much as he’s eager to face hitters without pain, without having to improvise an arm slot or wish for movement on a pitch, Cardinals lefty Jaime Garcia will return to the mound this week with something else besides a healthy shoulder.

He spent a couple of seasons learning how to compete without one.

“I’ve learned just as much from bad things, the injuries, just as I have from the good things,” Garcia said in the Cardinals’ clubhouse Monday. “The last two years have been tough, real tough. My shoulder wasn’t right. The thing was I was still able to do sometimes was to go out there and focus on getting it done. There are no excuses once you’re on the mound. You’ve decided to take the ball that day and you find a way.”

Garcia played a light game of catch Monday as unofficial workouts continued for a handful of Cardinals who have reported early to the team’s facility at Roger Dean Stadium. Michael Wacha, the National League championship series MVP, arrived, and several pitchers, including Adam Wainwright and Lance Lynn, got on the mound to throw a side session. The club’s first official workout of spring training is Thursday, and pitching coach Derek Lilliquist said 13 pitchers will take the mound for bullpen throws that day.

The rest, except for reliever Jason Motte, will throw Friday.

Garcia will be one.

The lefty, who won 13 games in back-to-back seasons and finished third in 2010’s NL rookie of the year voting, had his season ended last May by shoulder surgery that was a couple of years in the making. Garcia pitched through the injury in 2012, and he reported to spring training a year ago having attempted a non-surgical rehab for the joint. In May, he relented and had a tear of his labrum repaired. He was throwing off the mound by the end of the season, and he’ll start spring training this week on the same schedule as the other starters, unless his shoulder does not respond to its first test Friday.

“I decided to pitch, to take the ball when I could” last season, Garcia said. “I don’t have any regrets. I don’t. I learned from the good. I learned from the bad. Now I know the arm is good.”

In many ways, Garcia’s shoulder could be the joint around which the Cardinals’ rotation competition spins. The Cardinals return all four of the starters used in the postseason and Shelby Miller, the righty who won 15 games as a rookie last year. Garcia is the only lefty of the group – something manager Mike Matheny has said he would like to have if all other things are equal. Team officials have said it’s an open competition for spots in the rotation after ace Wainwright, and that if healthy Garcia, with his past success, is a better fit for the club as a starter.

He enters the season as the second-highest paid pitcher on the staff after Wainwright. An escalator in the extension he signed several years ago gives him a $7.75 million salary for 2014, behind only four players, all of whom have been All-Stars.

“I think first and foremost health is the biggest thing for Jaime right now,” Lilliquist said. “Get him into games and see what he looks in games. Health is definitely No. 1. But as long as his health is 100 percent, that’s going to do a lot for putting his mind at ease and knowing he can go out there and compete. That was a tremendous learning experience for him. Knowing that, hey, he’s doing what he could at 75 percent or 80 percent or whatever it was. Now he feels good. Now he feels 100 percent. He’s over the mental part of how’s it going to feel? Now he can focus on the competition.”

In the past two seasons, Garcia has made 29 starts and gone 12-9 with a 3.81 ERA.

He made nine starts in 2013, and he came out of a strong performance in spring training to win three of his first six starts and carry a 2.50 ERA into May. That’s when the shoulder sabotaged him – again.

Throughout the 2012 season, Garcia had discomfort in the shoulder, and he acknowledged Monday that he fiddled with his mechanics because he couldn’t find a comfortable arm slot that season. He had difficulty regaining strength after starts. His pitches, at times, felt flat, weak. He stopped throwing bullpen sessions. He couldn’t play catch without pain, but the pain did fade when he took the mound for a start. He was able to rehab and re-strengthen the shoulder in the offseason and pitched successfully through last March and April. Then the pain returned.

“It was pain. It was a lot of pain,” Garcia explained. “During the game. After the game. Pain every single pitch. I was still trying to find ways to get people out. My stuff was good. My mechanics were good. … But it was not fun. Not fun. Not fun having to go through that.”

After Dr. George Paletta repaired the labrum and corrected some damage to the rotator cuff, Garcia returned to the strengthening and rehab program that he had hoped would help him avoid surgery. He set a goal of being ready to pitch by the end of the season. Even though that was unrealistic it “helped me mentally to get to a normal offseason.” He was able to throw to hitters during team workouts in October. One club official described him as ready for a rehab assignment – if the season was a month longer.

Garcia’s offseason has included a few times off a mound already so that he could get a feel for it before coming to spring training. He will have been in Jupiter at the Cardinals’ complex 10 days when he takes the mound Friday. But he’s been there many times before. When they drafted him, he Cardinals gave him time to get healthy, and he responded by improving his physical fitness. When he needed Tommy John surgery and missed a year, he returned stronger and sporting a new two-seam fastball that has become his go-to pitch.

“Past setbacks and he’s always come back stronger,” Lilliquist said.

“Now it’s a matter of not losing that concentration,” Garcia said. “When you feel a little something, they say it helps you to stay focused a little more. I have to be cautious and not get satisfied and not get comfortable now that I’m healthy. Everything is not going to be easy now. It’s not. I have to keep that same mentality.

“Be healthy, and do my job.”

Derrick Goold covers the Cardinals and Major League Baseball for The Post-Dispatch. Follow him on Twitter at @dgoold or on Facebook at Facebook.com/BirdLandPD

Derrick Goold is the lead Cardinals beat writer for the St. Louis Post-Dispatch and current president of the Baseball Writers' Association of America.