The problem was discovered one year ago to the day Monday, according to Flowers. After consulting with White Sox head athletic trainer Herm Schneider, he has been doing the pitchers' shoulder program since.
"But there were a number of days in [Spring Training] where the pain was extreme," Flowers told a pool reporter by phone from Chicago. "It was a really tough [decision]. I've known I had to have surgery for a couple of months now. With the work I've put in to rehab, it was a good indicator. There was no way I could have continued with the pain level."
Flowers has seen three doctors over the past year, and had a recent MRI with contrast dye to pinpoint the issue.
"It solidified what I thought was going on," Flowers said. "As a ballplayer and an athlete, you know yourself better than everybody else. Initially when it happened, I thought it was more like a tweak. What got me was when I was getting ready for spring, it intensified, and that's when I started to question it.
"When [anti-inflammatories] wear off, you get the pain level and real feel. It was very extreme. It's something that has to be done. I could continue but couldn't perform at the level required by myself, my team or my teammates."
Getting the starting job with A.J. Pierzynski's departure via free agency was "definitely a driving force to exhaust every option I could," according to Flowers. Ultimately, Flowers finished the season with a .195 average, 10 homers and 24 RBIs, and will have to prove himself an everyday player once again next spring.
"You are looking at a guy that, defensively, he's been what you wanted and calls a great game," said manager Robin Ventura. "He does stuff around the plate that you like. Offensively, it's a down year. He's got to fight his way back offensively to be that guy. His potential is there to do it."
Scott Merkin is a reporter for MLB.com. Read his blog, Merk's Works, and follow him on Twitter @scottmerkin. This story was not subject to the approval of Major League Baseball or its clubs.