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06/21/12 7:35 PM ET

Duensing to make first start of year Saturday

PITTSBURGH -- Left-hander Brian Duensing will make his first start of the season on Saturday against the Reds, Twins manager Ron Gardenhire announced Thursday.

With Monday's off-day, the Twins went with a four-man rotation but needed a fifth starter against the Reds with right-handers Carl Pavano and P.J. Walters on the disabled list.

The Twins decided to go with Duensing, who has a 3.12 ERA with 22 strikeouts and nine walks in 34 2/3 innings as a reliever. He last pitched on Tuesday against the Pirates, when he tossed 1 2/3 scoreless innings in relief.

Duensing, who threw a bullpen before Thursday's game, is expected to be restricted to about 50-60 pitches because he hasn't had the chance to build up his pitch count yet.

"We decided to let him stretch out a little bit and piggyback him with a couple other guys and see what happens, how many innings he goes," Gardenhire said. "They got some pretty good left-handed hitters in that lineup, so you try a lefty over there too."

Part of the reason the Twins went with Duensing is because two of the top Reds hitters -- Joey Votto and Jay Bruce -- are left-handed. But Duensing also has improved against right-handers this season, as they posted a .947 OPS against him last year but have a .645 OPS against him this year.

Duensing, though, said he's not sure why he's been so much better against right-handed hitters this season.

"I don't know," Duensing said. "Maybe I'm making some better pitches. When I've gone in, I've gone down and in instead of up and in. I've been throwing strikes in there, and they have to be aware of that instead of disregarding that and look middle away. ... And I've had some good luck on top of it, too."

Duensing, who has made 50 career starts, including 28 last year, said he's hoping his return to the rotation is similar to both '09 and '10, when he joined the rotation to much success after starting out in the bullpen. He posted a 2.73 ERA in nine starts in '09, and had a 3.05 ERA in 13 starts in '10.

"If I could throw like that it'd be great," Duensing said. "I'm really hoping that will happen. I don't know. But hopefully I'll go out there and do well and give the team a chance to win and not hurt the bullpen too bad."

Mauer held out for third consecutive game

PITTSBURGH -- Twins catcher Joe Mauer was held out of the lineup for the third straight game on Thursday with a bruised right quad sustained in a home-plate collision with the Brewers' Rickie Weeks on Sunday.

Mauer was scheduled to catch a bullpen before Thursday's game but didn't because the swelling in his quad hadn't gone down.

He took batting practice before the game and jogged around the bases but said his quad hadn't improve much from Wednesday. But he added that he hopes to return at some point this weekend against the Reds.

"I hope so," Mauer said. "It's not much better than yesterday. I thought I'd be able to do a little bit more. It's real frustrating."

Mauer, who is available to pinch-hit, is batting .314, with a .415 on-base percentage and .427 slugging percentage in 60 games.

Hot-hitting Carroll out of starting lineup Thursday

PITTSBURGH -- Jamey Carroll has been one of the Twins' hottest hitters but was out of the lineup against the Pirates on Thursday, as Alexi Casilla got the start at second base.

Over his last 13 games, Carroll is batting .388 (19-for-49) with 12 runs and a .455 on-base percentage.

But Twins manager Ron Gardenhire said he wanted Casilla to get some playing time, as he was making just his second start since Friday.

"Everybody has to play here," Gardenhire said. "He's played well in his last couple of games here; he seems to do well in this role. So mix 'em up. We just have to keep mixing them up and give everybody an opportunity here."

Rhett Bollinger is a reporter for MLB.com. Read his blog, Bollinger Beat, and follow him on Twitter @RhettBollinger. This story was not subject to the approval of Major League Baseball or its clubs.