Minneapolis ? With their cleanup hitter and starting left fielder already sidelined with injuries, the Minnesota Twins took their biggest blow yet on Sunday.

All-Star catcher Joe Mauer was placed on the 15-day disabled list with a strained left quadriceps muscle after Sunday’s 4-3 loss to the Boston Red Sox.

Mauer had an MRI exam on Sunday morning and missed his second straight game. Test results revealed a strain, and the Twins recalled catcher Chris Heintz from Triple-A Rochester to take Mauer’s place on the roster. The move is retroactive to May 5.

The injury has bothered the reigning AL batting champion for most of the season, but it really flared up while he was running the bases in Friday night’s loss to Boston.