PITTSBURGH -- Chicago Cubs reliever Shawn Camp has been placed on the disabled list with a sprain in his right big toe, the team announced Wednesday.

"I guess it's been bothering him for about a month," manager Dale Sveum said before the Cubs played the Pittsburgh Pirates on Wednesday night. "He got treatment on Sunday to start the process, re-aggravated it and the inflammation got too bad. It was getting tough to push off the mound."

Sveum said the Cubs would have considered putting him on the disabled list before designating reliever Michael Bowden for assignment in order to activate Matt Garza from the disabled list. But the team didn't know the seriousness of the problem until it was too late.

"He came for treatment and we didn't know it was that extensive," Sveum said. "But that would have been the obvious move."

Bowden has to clear waivers before he can be reassigned. The Cubs recalled pitcher Rafael Dolis from Triple-A Iowa to take Camp's place. Camp gave up a grand slam to pinch-hitter Travis Snider in the Cubs' 5-4 loss to the Pittsburgh Pirates on Tuesday.

He appeared in 20 games with a 7.56 ERA after leading the league in appearances last season with 80. Sveum was asked if the injury could be a reason for his struggles this season.

"When you can't push off and it's that painful, you're going to lose something in your legs," Sveum said. "We have to get it calmed down."

Dolis has appeared in two games this season for the Cubs, pitching a scoreless 1 2/3 innings.

Camp elected to go back to Chicago to rest his toe while the Cubs continue on their road trip.