The St. Louis Cardinals have placed All-Star catcher Yadier Molina on the 15-day disabled list with a right knee sprain.

Molina has been bothered by knee issues since June and played three innings in the second game of Tuesday's doubleheader against Pittsburgh before being replaced by Rob Johnson.

The Cardinals sent him back to St. Louis for tests, which could determine a potential return date.

Molina is batting .330 with eight home runs, 30 doubles and 54 RBI in 98 games for the Cardinals this year.

The Cardinals also placed outfielder Shane Robinson on the DL with a right shoulder strain.

Robinson, who has appeared in 65 this season with the Cards, is batting .263 with two home runs while driving in 12 runs.

To fill their roster spots, St. Louis recalled outfielders Brock Peterson and Adron Chambers from Triple-A Memphis.

Peterson, 29, made his major league debut earlier this month, appearing in five games for the Cardinals. He was batting .305 with 67 RBI in 96 games with Memphis. His 23 home runs lead the Pacific Coast League.

The left-handing hitting Chambers is batting .252 overall this season at Memphis, hitting eight home runs and collecting 42 RBI.