Pelfrey, 30, is 0-3 with a 7.99 ERA and way more walks (18) than strikeouts (10) in 23 2/3 innings and five starts this season. There have been rumblings the team would drop him from the rotation, so the injury buys them time to evaluate other options.
Righty Samuel Deduno will move into the rotation for the time being. The 30-year-old has a 2.89 ERA in 18 2/3 relief innings this year. He has made 33 starts for the Twins over the last two seasons.