PHOENIX -- Adam Rosales' crutches are gone, but his rehab process is not over.

With his doctor's blessing, the A's infielder rid himself of crutches on Thursday -- "I threw them in the dumpster," he said -- but he will sport a walking boot for at least another two weeks and could possibly not return to the team until May 1, manager Bob Geren said Friday.

Rosales, 27, underwent right foot surgery on Dec. 8, when debris was removed and two screws were inserted to aid in the healing process, which has become lengthier than he initially expected.

"As hard as he would push, as hard as he would work and try to speed it up and be ready for the season," Geren said, "it's more of a healing thing where you want to hold him back."

With Rosales essentially out of the Opening Day mix, Geren will now turn his focus toward a handful of infielders that can fulfill his utility role come season's start. Eric Sogard, Steve Tolleson, Andy LaRoche and Josh Horton are the leading candidates, he said.

"Obviously," Geren said, "I'm going to need somebody that can play third, short and second."

In an ideal world, the chosen one would boast an impressive glove at shortstop, as Cliff Pennington is coming off left shoulder surgery. Horton, who will turn 25 on Saturday, has the most experience at the position and is highly regarded defensively, though he's never played above Double-A.

Sogard and Tolleson have spent time at shortstop as well. Tolleson may have the upper hand because of his ability to play all three positions, but the club is also very high on Sogard, primarily a second baseman.

The newly acquired LaRoche, meanwhile, is the only player of the bunch without shortstop experience, but Geren said he'll receive just as long of a look. The 27-year-old brother of Nationals first baseman Adam LaRoche hit .206 with four home runs and 16 RBIs in 102 games with Pittsburgh last year. Fifty-two of his 58 starts were at third base; he also made appearances at second base and first base.

Outside of those four, 2009 first-round Draft pick Grant Green appears to be the next best option, but Geren noted the organization would prefer to avoid rushing his grooming process. Green, who played for Class A Stockton last year, is said to be far more advanced offensively than defensively and may be a year away from big league action.

Sogard is currently the only one on the club's 40-man roster, though Geren said that will play no factor in his final decision.

"The best guys will be on the team," he said.