OAKLAND -- Brandon Allen may be just the power hitter the Oakland Athletics heave been searching for since the beginning of the season.

At least, that's how A's manager Bob Melvin would like to see it played out.

Allen, whom the A's acquired in a trade that sent right-handed reliever Brad Ziegler to the Arizona Diamondbacks, was recalled to the Majors before Saturday's game against the Texas Rangers and inserted into the starting lineup at first base.

"He's a talented guy who has power," Melvin said. "He's a good athlete who can play first base and left field. He can also be used as a left-hander off the bench in a pinch-hitting role."

Allen was hitting .306 with 18 home runs and 66 RBIs with Triple-A Reno when he was called up by the D-backs less than two weeks before the trade.

"He walks and he gets on base," Melvin said. "He's definitely a guy who can be productive. He's a work-in-progress, and we'll have to see how things shake out."

Melvin assured Conor Jackson that the first-base job is still his to lose. The manager said he was being given a scheduled day off after hitting a pair of doubles and driving in the A's lone run Friday night.

"What Conor has done warrants him to be the everyday first baseman," said Melvin. "We can use Brandon in the outfield mix."

The A's also brought up right-hander Bruce Billings to give Melvin flexibility with the long role out of the bullpen.

Billings came to the A's as part of the trade that sent infielder Mark Ellis to the Colorado Rockies.

McCarthy sore, but completes pregame routine

OAKLAND -- The way Brandon McCarthy fell to the ground after getting hit on the right knee by Endy Chavez's line drive in the fourth inning of Friday night's game made it appear as though he was seriously injured.

That the ball caromed down the right-field line into the Rangers' bullpen seemed to emphasize that.

"Actually, I didn't know I had been hit by the ball until later," McCarthy said. "My back locked up and I was fighting a spasm at the time. That's why I went down. It was only when I tried to sit up that I realized I had been creamed."

McCarthy left the game at that point and walked off, with a slight limp, under his own power.

"It's a little sore," said McCarthy, who went through his regular pregame routine to test the right knee.

A's make room on roster for Allen, Billings

OAKLAND -- To make room for Brandon Allen and Bruce Billings on the roster, the A's sent infielder Adam Rosales and left-hander Jordan Norberto to Triple-A Sacramento.

Norberto pitched two innings in relief on Friday night, and Brandon McCarthy's early departure necessitated a move to bolster the bullpen.

"I can see him back in the big leagues," manager Bob Melvin said of Norberto. "We were a little concerned about his ability to go more than an inning but he handled it just fine."

Rosales has not been able to get on track this season after spending most of the first half on the 60-day disabled list. He was hitless in his last 25 at-bats, with an overall average of .083.

"He didn't have a Spring Training, and he fell behind," Melvin said. "He's going down to play all over -- third base, shortstop and second base. There's no doubt in my mind he'll be back Sept. 1, if not before."