Milwaukee, WI (SportsNetwork.com) - St. Louis Cardinals pitcher Adam Wainwright was placed on the 15-day disabled list Sunday with an Achilles injury.

Wainwright was hurt in the fifth inning of Saturday's game against Milwaukee after taking a swing at the plate. He popped up and started to run toward first when the injury occurred.

"I thought I got hit by something," said Wainwright after Saturday's game. "If you look at the replay, I kind of get out of the box and I look back thinking, 'Gosh, the catcher's mask must have hit me. The bat must have hit me or something.'"

Instead, Wainwright was helped off the field and was in a walking boot after the contest. He is expected to undergo further tests on Monday when the Cardinals return to St. Louis.

The Cardinals are calling it a left Achilles and left ankle injury. If it is a serious Achilles injury, the right-hander could be sidelined for a while -- possibly the remainder of the season.

Wainwright had held Milwaukee scoreless through his four innings of work on Saturday, yielding three hits with four strikeouts while facing the minimum 12 hitters.

In four starts this season, the 33-year-old veteran has a record of 1-2 with a 1.44 ERA.

The Cardinals recalled catcher Cody Stanley from Triple-A Memphis to fill the roster spot.