The right-hander won 12 times with a 3.77 ERA over 217 innings for Washington in 2005. He also made an important start for Oakland during an ALDS three-game sweep of Minnesota in 2006.
Now, the 14-year veteran with 126 victories seems to be at a crossroads in regard to his career.
Loaiza was returned on the Fourth of July from an injury rehab assignment for a sore right shoulder with Triple-A Charlotte. He has rejoined the team to have his shoulder examined by White Sox doctors, as soreness persists, but he also will be watched by pitching coach Don Cooper and manager Ozzie Guillen over the next few days to a week to see if there's still a place for him on the White Sox staff.
"Then we make the decision if we keep him here, send him to the Minors or let him go," said Guillen of Loaiza. "It's very important for him and us.
"I don't like to play with players. You are going to help us or you are not. We are going to keep a close look on him and make a decision next week."
Prior to Sunday's series finale with the Athletics, Loaiza threw a bullpen session under Cooper's watch. Loaiza was placed on the disabled list on June 13, after the White Sox had signed him to a one-year contract on June 4. Velocity and arm strength were a problem for the long relief/spot-starter role the White Sox had in mind for Loaiza, who was clocked in the high 70s and low 80s mph.
Adam Russell's emergence in Loaiza's absence also will make the White Sox decision a tough one.
"You never know how it can turn in the second half of the season, and if something happened, I would like to have some insurance," said Guillen, pointing primarily to his starting rotation. "To be honest, I don't make the decision.
"That decision will be made by [Loaiza]. That's why we have to see how he's doing."
Scott Merkin is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.