"This spring, the volume of A's questions might exceed space available in The Chronicle to ponder them.

More than a quarter of the team's 40-man roster is new, with more to come when outfielder Yoenis Cespedes' deal is official and if the team signs designated hitter Manny Ramirez.

The rotation is unsettled, and so too is the closer spot. First base is up for grabs among four players.

And the A's have less time than usual to figure everything out: The club leaves for Japan on March 21 and the season opener is March 28 in Tokyo.

For brevity's sake, here are the A's top five questions as pitchers and catchers report to Phoenix Muni today:

1. Who will play first base? Brandon Allen showed flashes of great potential after being acquired from Arizona on July 31, but he was not consistent. Daric Barton underachieved for more than two months, was sent to Triple-A Sacramento, and shoulder surgery ended his season. Chris Carter has yet to show he can handle a big-league role in several brief call-ups, and Kila Ka'aihue, picked up on waivers at the end of last season, is new to the team.

Initially, the team was looking at Ka'aihue to pick up some at-bats at DH, but the arrival of Cespedes will probably push Seth Smith from the outfield to more of a DH role (along with Jonny Gomes), so Ka'aihue's best shot is at first. This race is wide open. The A's seldom go on spring training results alone, but this spot might be the exception - the last man standing will be playing first base on March 28. And those not up for a fierce competition will be among the first cuts."