"I wish I knew -- I would change whatever it was," Coghlan said. "It just started feeling tight during the game. I could play tonight, but why? You've got 162 [games]. Get treatment, do regular routine, get treatment and go play on Sunday."
If Coghlan is healthy, the Cubs have three players -- Ryan Sweeney, Matt Szczur and Jonathan Herrera -- battling for two spots.
Szczur, a right-handed hitter, batted .362 (17-for-47) with five home runs, two doubles, two triples and three stolen bases in 21 games this spring, while Sweeney, a left-handed hitter, batted .200 (7-for-35) with three doubles and one stolen base.
Herrera, a non-roster invitee who has played for the Rockies and Red Sox, batted .300 (12-for-40) in 21 games and would be a valuable addition because he can back up at second and short.
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.