Capps woke up with more discomfort in the joint on Sunday, after working an inning on Saturday against the Cincinnati Reds. That's the only time he's pitched in the last 10 days.
The 28-year-old right-hander, enjoying a bounceback season after a rough time in 2011 that led to losing his ninth-inning role, said the return of the pain on Sunday made him nervous.
"After taking a week of not throwing, I expected it to be a lot better," Capps said before the Twins faced the Chicago White Sox on Monday.
He's eligible for reinstatement on July 9. The Twins will use a combination of lefty Glen Perkins and righty Jared Burton to close for now. Whoever pitches the eighth inning, depending on batter matchups, the other will work the ninth.
"Nobody wants to go on the DL. That's kind of a no-brainer. This is my job. I don't want to be sitting around," Capps said, adding: "But sometimes this is what it takes to get right. I'm not going to do anybody any good going out there hurt trying to pitch through it."
The Twins recalled lefty Tyler Robertson from Triple-A Rochester to fill the roster spot. Robertson, a third-round draft pick in 2006, went 2-2 with a 3.77 ERA in 33 relief appearances for the Red Wings. He's never pitched in the majors before.