Perez initially felt a small knot in his shoulder while playing catch Tuesday but opted to try to work through it, pitching in a game against Kansas City later that day. The next morning, however, when he attempted to play catch again, the shoulder was too sore to throw. That was when he knew something was wrong. An MRI later confirmed his suspicions.
The 27-year-old originally called being selected to represent Team USA in the Classic the biggest honor of his career thus far, but Saturday he said the tournament was not worth jeopardizing his season with Cleveland.
"It would be selfish of me to put my wants of playing in the Classic above what the rest of the team is doing," he said. "It's disappointing, but at the same time, it would've been a lot worse to pitch through it now, then miss three months of the season. I can get over not pitching in the Classic. It was a tremendous honor to be chosen, but I can get over it."
Because of the Classic, Perez began his baseball activities much earlier this season than he normally would, but he does not believe that contributed to his injury.
"It was the same; I just started them earlier," he said. "There's nothing you can do to manage injuries. The only way you can stay healthy is not pitching."
For what it's worth, Perez is not as worried about this injury as he was last spring, when he sustained an oblique strain in his first bullpen session and was sidelined from Cactus League action until March 29. The closer logged only three official innings in three appearances before joining the Opening Day roster.
"I was more concerned last year because I wasn't able to pitch through it," Perez said. "I pitched Tuesday, though, with this, and it didn't make it worse. Plus, it's gotten better every day I've come in, so that's a good sign. Noticeably better."
Perez will not pick up a ball for the next week as he tries to give the injured muscle some rest before beginning his comeback. The timetable for his return is roughly three to four weeks, but the right-hander said he would know more once he begins playing catch again.
"If I feel good, we can accelerate it more at the end, just right now it's a slow, boring process," he said. "We're playing this a lot slower than we would if it were June or July in the middle of the race."
Knowing how important the Classic was to Perez, Indians manager Terry Francona was pleased with how his closer handled the situation.
"I thought he was very mature about it," Francona said. "The minute he felt something, he told us. And he was as honored as anybody to [be picked for the Classic]. I remember when I got that first phone call from him, he was off the charts. So I appreciated his honesty, because I know it was hard for him."
Whether Perez will be ready for Opening Day will not be known for a few weeks, but even if he does miss the start of the season, it will not bother the pitcher too much.
"Everyone wants to point to Opening Day, and rightfully so, but if I miss the first series, in the long run, that's not that bad," he said. "My goal is to not miss any games, but it's early. There's no reason to push it just for April. If there is any lingering issues, I'm not going to just try to get ready for Opening Day, I'm trying to be prepared for a six- hopefully seven-month season."
Perez totaled 39 saves last year to go with a 3.59 ERA over 57 2/3 innings.