CINCINNATI -- Miguel Andujar did everything he could to keep playing through the pain.

Prior to Wednesday’s game in Cincinnati, A’s skipper Mark Kotsay confirmed the 29-year-old Oakland left fielder will have surgery to repair a core muscle injury and is done for the season.

“Miguel's been playing with this issue for a few weeks,” Kotsay said. “It's a credit to Miguel and testament to the character of the young man, really, to continue to play. It just got to a point where it was uncomfortable sleeping and impacting his daily life as well.”

Andujar, who was placed on the 10-day injured list retroactive to Sunday, has played in 75 games this season, the second-highest total of his eight seasons in the Majors. Andujar was slashing .285/.320/.377 in those 75 games with four homers and 30 RBIs.

Taking Andujar’s place on the roster is Nick Allen, recalled from Triple-A Las Vegas for his second stint with the A's this year after batting .345 with seven homers and 51 RBIs in 81 games for Las Vegas. Allen was on the Opening Day roster and batted .171 with a home run and three RBIs in 28 games before he was optioned to Las Vegas on May 3.

On a team stocked with young developing talent, Andujar was the perfect fit for Kotsay and the perfect answer against left-handed pitching.

He was batting .411 (23-for-56) against southpaws, with a .995 OPS.

“I think we are going to miss him,” Kotsay said. “He really was a big contributor and a big part of this club’s success over the last few months. And hopefully the surgery will go well and he'll get back here. He won't get back this season. He'll be done this season. But we'll definitely look forward to having him hopefully next year.”

Also filling in will be Daz Cameron, who started Wednesday’s game.

“Daz will be there right now, you know, we do like to match up, and we'll look into the roster and bringing Nick here. Nick's done a great job since he was sent back to Triple-A, and with Daz on the roster, with [Tyler] Nevin able to play outfield, and also with [Seth Brown] at first, he's also an outfielder, got some flexibility and things that we can do,” Kotsay said.

“Nick's just had a really nice season in Triple-A. He's put up some really nice numbers, and this is a deserving call up for him.”