DETROIT -- The Tigers recalled left fielder Carlos Guillen from his Minor League rehab assignment on Tuesday, but he isn't coming back to the Tigers roster quite yet. Instead, he's heading to Triple-A Toledo to pick up his stint on Wednesday after having his sore right shoulder examined by doctors on Tuesday in Detroit.

No structural damage was found, but Guillen and the club wanted to be cautious. The recall showed they were concerned enough about the shoulder to make a move. Instead, since he'll be back out on rehab Wednesday, the recall move was essentially revoked. He'll have up to 11 days remaining in his assignment before the Tigers have to decide whether to activate him, though it probably won't take that long.

"He's going to go down there and hit for a few days," manager Jim Leyland said, "then we'll re-evaluate after that."

Guillen went on the 15-day disabled list in early May with inflammation in his right shoulder, later diagnosed as the result of years of playing shortstop and throwing. After experiencing little to no progress for several weeks, Guillen and team medical staff said they would keep trying to get him back until the All-Star break before approaching the possibility of shoulder surgery.

Guillen's progress over the last few weeks raised realistic hopes that he might not just get back to playing this season, but could even be back with the Tigers by the end of July. He went 3-for-12 with a double and four walks over five rehab games for Class A Lakeland last week, with almost all of that damage in his final three games after starting out 0-for-6.

Guillen reported soreness in his shoulder, including when he swung from the right side. The Tigers' original hope was to promote Guillen from Lakeland to Toledo on Monday, but his shoulder concerns put that on hold.

"There was some soreness," Leyland said, "but evidently he's good enough to go down and hit tomorrow. I think we'll play it by ear."

Guillen was upbeat about his situation when he arrived in the Tigers clubhouse Tuesday afternoon.

"It feels better. It feels good," Guillen said of his shoulder. "It just takes time. When you come back, you're not going to feel the same way every day. I know my body. I feel better."

How he feels as he progresses in rehab could be big in how the Tigers proceed for the home stretch. For an offense that has struggled to score runs for most of the season, Guillen has the potential to have the effect of a Trade Deadline acquisition. However, that hinges on a return to the healthy Guillen of old, rather than the injury-hampered Guillen of this season.

In other injury news, Leyland said reliever Joel Zumaya is still hurting after reporting pain in his shoulder following Friday's game against the Yankees. The Tigers want to get the pain down before determining whether he'll need rest or surgery to fix.

Meanwhile, both Nate Robertson and Jeremy Bonderman threw Tuesday in their rehab work towards potential late-season returns. Robertson played catch from 120 feet, three weeks after undergoing surgery to remove four masses from his left elbow. Bonderman threw a five-minute bullpen session Tuesday and felt fine.