"Big bat, a lot of pop," manager Joe Maddon said before Thursday's series finale against the Blue Jays. "I know he's had a little bit of a swing-and-miss issue historically. But he's also had big power. We've done some work on it. We have some ideas in regards of how to approach this whole thing."
Maddon said Allen is primarily a first baseman although he has also played the outfield.
"I heard he's a great guy," Maddon said. "I heard he's an 80 makeup guy, which is the highest grade you can give an athlete. I'm looking forward to meeting him. I don't know him at all except from what I've heard. But he sounds like he fits our profile."
Maddon said he was not certain yet how Allen would be used.
"The big thing I know is that his bat plays really big," he said. "He's carried some pretty big Triple-A numbers. We have ideas."
Allen was designated for assignment on April 9 to make room for first baseman Daric Barton who was returning from the disabled list. The A's acquired Allen from the Arizona Diamondbacks as part of a deal for pitcher Brad Ziegler at last year's trade deadline.
He has spent parts of four seasons in the majors, batting .205 (68-for-331) with 11 HR, 38 RBI and 40 walks in 109 games with the Diamondbacks (2009-11) and A's (2011-12). He was 0-for-7 with five strikeouts in three games with the A's this season.
Over eight minor-league seasons, Allen has hit .268 with a .355 on-base percentage and 142 home runs in the Chicago White Sox, Diamondbacks and A's organizations. Last season he hit .299 (103-for-344) with 21 HR and 72 RBI in 93 games split between Triple-A Reno (Diamondbacks) and Triple-A Sacramento (A's). He was selected by the White Sox in the fifth round of the 2004 First-Year Player Draft and was dealt to Arizona on July 7, 2009 for Tony Peña.
To make room for him on the 40-man roster, catcher Robinson Chirinos has been transferred to the 60-day disabled list.