CINCINNATI -- Twins closer Matt Capps hasn't been on the disabled list since 2008, but it looks like he's heading there now after having a setback with his right shoulder.

Capps pitched Saturday for the first time since June 15, and the soreness returned to his shoulder while he was sleeping. He expects to have an MRI exam in Minnesota on Monday, and Manager Ron Gardenhire said the team likely will have a pitcher from the minors joining them for the start of the White Sox series.

"I've pitched through a lot of things, and this is not something I feel like I can comfortably pitch through," said Capps, who is 1-4 with a 3.42 ERA and 14-for-15 in save opportunities. "I've prided myself most of my career on being able to take the ball every day, and that's the hardest thing for me, stitting in the cluhbouse or sitting in the dugout, watching my teammates play, knowing I can't do anything to help."

Gardenhire said he doesn't want to name an interim closer before talking to his relievers first, but he said they'll probably stick with Jared Burton in the eighth and Glen Perkins in the ninth, since that's been working. He did say he could switch it up depending on matchups.

Rotation update

Gardenhire said P.J. Walters likely will have to make a minor-league rehab start before rejoining the Twins rotation. Gardenhire said Brian Duensing is in the rotation to stay, for now, though it's uncertain when he'll make his next start with another off day coming Thursday.

The Twins have a doubleheader on Saturday against the Royals, and Gardenhire said they'll likely need another starting pitcher that day. Teams can expand their active roster to 26 players for a doubleheader.

Pavano update

Carl Pavano (rotator cuff weakness) has regained strength and should be ready to start a throwing program this week, assistant GM Rob Antony said.

Big swing game

The Twins close interleague play Sunday with a chance to win a series against the National League Central-leading Reds.

The Twins are 8-9 in interleague play and have lost three consecutive series, so I'm pegging this as a potential emotional swing game. They'll have their most reliable starting pitcher on the mound, in Scott Diamond, and after shooting blanks against Johnny Cueto on Saturday, they'll be facing a very beatable righthander in Mike Leake.

After starting the season 0-5 with a 7.11 ERA, Leake has been better of late, going 2-0 with a 2.93 ERA in his past seven starts. Leake, 24, went right from Arizona State to the big leagues after the Reds made him the No. 8 pick in the 2009 draft and is now 22-18 for his career.

TWINS (28-42)

1. Ben Revere, CF
2. Darin Mastroianni, RF
3. Joe Mauer, C
4. Josh Willingham, LF
5. Justin Morneau, 1B
6. Trevor Plouffe, 3B
7. Brian Dozier, SS
8. Alexi Casilla, 2B
9. Scott Diamond, LHP (5-3, 2.57 ERA)

REDS (38-31)

1. Chris Heisey, CF
2. Wilson Valdez, SS
3. Joey Votto, 1B
4. Brandon Phillips, 2B
5. Jay Bruce, RF
6. Ryan Ludwick, LF
7. Todd Frazier, 3B
8. Devin Mesoraco, C
9. Mike Leake, RHP (2-5, 4.70 ERA)

Great American Ballpark. First pitch: 12:10 p.m. (Central). TV: FSN. Twins Radio Network

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