The Tigers announced Monday that Willis will return to Detroit in the next day or so to have his right knee examined by team doctor Stephen Lemos. It's the same knee that he hyperextended in April when he slipped off a wet pitching mound in Chicago, forcing him onto the 15-day disabled list. It is apparently bothering him again.

The news is the latest development in the brief, but tangled Detroit tenure for the former 20-game winner whose difficulty spotting his fastball has become a saga in the Motor City and a potential career challenge for him.

Willis agreed four weeks ago to accept an option to Class A Lakeland as part of a program to try to get him back to his old form after back-to-back five-walk outings in starts for the Tigers. The latter of the outings saw him record more walks (five) than outs (four) in a nationally televised matchup on June 9 against the Indians, who used a pair of home runs to score eight runs against him.

In five outings this season, Willis has walked 21 batters over 11 1/3 innings, allowing 13 runs on seven hits with five strikeouts and recording a 10.13 ERA.

After a couple weeks in Lakeland working with pitching instructor Jon Matlack, Willis returned to the mound in a game for the first time in a relief appearance for Class A Lakeland on June 29. He allowed a run on a hit and three walks over two innings, but seemed to settle down in his second inning of work.

He hasn't pitched in a game since, presumably in part because of the knee discomfort. It's unclear at this point, however, how long the knee had been bothering him.

The Tigers didn't put a timetable on Willis' return when they sent him out, so this setback doesn't necessarily affect president/GM Dave Dombrowski's plans. The focus upon sending Willis to Lakeland was that he wouldn't return until he was in good form again, and that they wouldn't rush the program. Given the three-year, $29 million contract the Tigers and Willis signed last offseason, there isn't time pressure.

Armando Galarraga has posted a 7-2 record since filling Willis' spot when he went onto the disabled list in April. Since Willis went to Lakeland, ex-farmhand Eddie Bonine's ability to pitch for ground balls and outs has produced some relatively surprising results in the Tigers rotation. He has posted a 2-1 record and 4.30 ERA over four starts, including back-to-back quality outings against the Padres and Rockies late last month.

The Tigers are expected to look at their pitching options and trade possibilities as they near the July 31 Trade Deadline. The challenge on that end, however, would be to make a deal without further emptying a farm system that lost more than a handful of prospects in trades last offseason, including the six players the Tigers sent to Florida last December to bring in Willis and slugger Miguel Cabrera.