DETROIT -- Tigers third baseman Carlos Guillen is making progress in his slow battle with a sore lower back, but any return to game action this season still seems a good bit -- and a few batting-practice sessions -- away.

Guillen was able to run, throw and do some light swinging with an athletic trainer over the weekend at Comerica Park. He was able to do some light swinging Monday with the Tigers hitting in the cage, but nothing extensive.

Manager Jim Leyland said Monday night that he expected Guillen to miss at the least the rest of the series, but wouldn't rule out a possible return this weekend at Chicago.

More than anything, the team's medical staff is going to proceed according to how Guillen feels. He has missed the Tigers' last 13 games.

Guillen hasn't played since Aug. 25 against the Indians after feeling soreness in his lower back and in both of his hamstrings. He missed time with similar issues earlier in August, but came back briefly to play. His back has been an issue on and off for much of the season, another reason why the Tigers will proceed slowly with this latest flare-up in hopes of eliminating it heading into the offseason and have him at full strength next spring.

Guillen is batting .286 with 10 home runs and 54 RBIs in 113 games this year. Mike Hessman made his fifth start in Guillen's place Monday.