SEATTLE -- Bartolo Colon's return engagement with the White Sox came to a quiet conclusion on Wednesday, when the team requested waivers on the right-hander for the purposes of granting his unconditional release and reducing the 40-man roster to 38.

The 36-year-old had not started a game since a July 24 loss at Comerica Park, which stood as just one of three appearances for the burly hurler since the start of June. Colon was a low-cost (one-year, $1 million), low-risk investment when the White Sox first brought him in as a free-agent candidate for the starting rotation prior to the 2009 campaign.

But Colon finished with a 3-6 record and 4.19 ERA in 12 starts, battling through too much reliance on a fastball that didn't have the same life it did in his prime, left knee soreness and a right elbow inflammation that sent him to the disabled list. The latter injury has kept Colon out of action since July 25.

His injury-induced absences became the source of occasional comic fodder during manager Ozzie Guillen's pregame media chats, as Guillen would address how the pitcher was missing in action from time-to-time. But according to Guillen's comments Wednesday at Safeco Field, he knew Colon's last elbow injury had a finality to it in regard to Colon's time with the White Sox.

"When Colon went down for the last time, I knew for a fact that he wasn't going to be back here, at least this year," Guillen said. "I knew that because he had to go through a rehab assignment, Freddy [Garcia] was throwing, Jose [Contreras] was throwing at that particular time.

"We had so much on the schedule, I knew it would be tough for [Colon] to come back here. I'm not going to say I erased him off the team, but I erased him from my mind because I had more problems to resolve. I had enough problems here."

These seemingly decent numbers for Colon were a bit misleading in the sense that he allowed a team-worst 13 unearned runs in 62 1/3 innings. During a 20-1 home loss to the Twins on May 21, as an example, Colon yielded eight runs on seven hits in two innings, but only one was earned.

Nonetheless, Colon provided the White Sox four quality starts during his stint on the South Side this year and a temporary fill at fifth starter. It wasn't exactly a comparable effort to Colon's nine complete games with the White Sox in 2003, but then again, Colon is a different pitcher this year -- coming off offseason surgery to remove bone chips from his right elbow.

"In the beginning, we thought he could help us and we had a plan for him because we knew he would have problems going through the season," Guillen said. "But, in the meanwhile when he got hurt, he told me a couple days before that he couldn't pitch. That's when we had to move someone out there.

"I think if we have a problem [with Colon], it's not the White Sox way. When we have a rehab program, you have to be monitored by us, monitored by [White Sox athletic trainer] Hermie Schneider. Whenever Hermie sends down there to say, 'This is what we want you to do.'

"He never went along with the program. I think that cost the trust of him and the trainers here," Guillen added. "He wasn't found and then one day he showed up and the next day he doesn't. He's supposed to do this, this, this and that, and he didn't do it. He did show up, but he wasn't following the program the way it was demanded. That wasn't seen as very good in the White Sox eyes."