PHOENIX (AP) -- The Oakland Athletics could finish somewhere in the middle of the pack in fielding percentage this season and it would be a vast improvement over last year, when they were worst in the American League.
The A's plan to feature three starting infielders that were not on last year's opening-day roster, two of whom were with other organizations.
Scott Sizemore was expected to provide stability at third base but that changed when he sprained his left knee Saturday, exposing the lack of depth at the position. The problem is so glaring, A's manager Bob Melvin asked catcher Josh Donaldson, who last played third base at Auburn in 2007, to focus full time on the hot corner.
Melvin will have to use minor leaguers to fill in when preseason games start this weekend.
"We don't have enough infielders," Melvin said Monday. "I'm worried that if we give guys days off we'll have to pick up guys from mini-camp. In fact, I know we will."
Jemile Weeks gave the A's instant offense when he was called up, but his play at second base left plenty of room for improvement. The A's also hope Brandon Allen, at first, and Cliff Pennington, at shortstop, can make some strides defensively.
Eric Sogard and Adam Rosales, two proven major league infielders, will get work at third. Melvin thinks their value, though, is in their versatility.
"They are going to have to play all different positions," Melvin said. "Donaldson is the only one who will not be moved around. He'll remain strictly at third."
The A's used six third basemen last year, with Sizemore taking care of the bulk of the games. Kevin Kouzmanoff was last year's opening-day roster. He was eventually sent down to the minor leagues.
Donaldson, originally drafted in the first round by the Chicago Cubs, senses an opportunity to make the 25-man roster out of spring and has immersed himself in the position.
"He has been working double time," Melvin said. "I can see a different pep in his step. He's intriguing there because he has some power and has been known to drive in runs."
Weeks was promoted to the big leagues "sooner than expected," A's general manager Billy Beane said. He was an immediate hit, relieving some of the fan angst from losing the popular Mark Ellis in a trade to the Colorado Rockies.
Weeks committed 13 errors, the fourth most by a second baseman last year. Ellis, by contrast, made the fewest miscues and led the majors with his .995 fielding percentage at the position.
"Weeks' double play turns are so much better than we saw last year," Melvin said. "His mechanics are so much better. He came in confident because of what he did last year. He has made significant strides in his defense."
Daric Barton, recovering from right shoulder injury, is another possibility at first. He committed eight errors last year, tied for sixth most in the majors, in 65 games. Allen had a slightly better percentage (.991) and has better power potential.
Wes Timmons, a non-roster player, is also in the mix at third, though Melvin prefers he remain flexible.
The A's have 19 outfielders and 10 infielders in camp.