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05/03/12 7:46 PM ET

Rookie reliever Hoover impressing Reds

CINCINNATI -- His time in the Majors has been brief thus far, but rookie reliever J.J. Hoover has been impressive. Over four innings in three appearances entering Thursday, Hoover has yet to give up a run.

"I'm getting there," Hoover said of his comfort level in the big leagues. "I'm still getting those adrenaline rushes out of the way. I try to stay within myself. My first couple outings, it kind of got away, and I was rushing to the plate and everything. But I'm ironing those things out now."

Hoover was acquired in the April 1 trade that sent third baseman Juan Francisco to the Braves.

During Wednesday's 3-1 loss to the Cubs, Hoover pitched a 1-2-3 ninth inning. He struck out Reed Johnson with a 94-mph fastball for the final out.

"When I'm out there, I just think to be ready when the phone rings," Hoover said. "I never want to be caught unaware."

Baker finds playing time for bench vs. Cubs

CINCINNATI -- For a variety of reasons, Reds manager Dusty Baker wrote a lineup on Thursday morning that was a departure from the norm.

Center fielder Drew Stubbs was not in it, nor was third baseman Scott Rolen, shortstop Zack Cozart and catcher Ryan Hanigan. Against Cubs starter Ryan Dempster, Chris Heisey started in center field and led off, while the struggling Willie Harris played third base, Wilson Valdez was at shortstop and Devin Mesoraco was behind the plate.

"We've got a lot of [baseball to play], and you have to get some guys playing time so they're ready when you need them," Baker said. "Sometimes you do it one at a time, and sometimes you do it as mass substitutions. Plus, the guys I am not playing haven't had a whole bunch of success against Dempster."

Stubbs entered the day in a 0-for-14 funk and was 4-for-21 lifetime (.190) vs. Dempster.

"Drew was going pretty good, and now he's starting to scuffle a little bit," Baker said. "I want to stop it before it gets chronic."

Stubbs was on a tear for a while, especially when he batted second in the order, where he was 13-for-39 (.333) with one homer and six RBIs.

One player who really needs to get going is Harris, who entered the day batting just .097 (3-for-31) this season.

Cairo begins rehab assignment at Class A

CINCINNATI -- Reds utility infielder Miguel Cairo, who has been on the disabled list with a strained left hamstring, left for Class A Dayton to start a rehabilitation assignment. Cairo will play Thursday night, Friday and Saturday.

"If everything goes right, I will meet the team in Milwaukee," said Cairo, who turns 38 on Friday.

Cincinnati begins a three-game series vs. the Brewers on Monday at Miller Park. Cairo is expected to get four at-bats per game to test his leg.

"The big thing is playing defense and reacting to balls and running the bases when you get a hit," said Cairo, who went on the 15-day DL on April 17.

Worth noting

Reds manager Dusty Baker was saddened over the news that former NFL linebacker Junior Seau died of what was reported to be a self-inflicted gunshot wound to the chest on Wednesday. Seau was 43. Baker had spoken to some people he knew from the Chargers, Seau's former team.

"I knew him. We weren't tight buddies, but I knew him through guys I knew over there for a long time," Baker said. "You saw the pain that was in his mother's eyes and everything."

Mark Sheldon is a reporter for MLB.com. Read his blog, Mark My Word, and follow him on Twitter @m_sheldon. This story was not subject to the approval of Major League Baseball or its clubs.