OAKLAND -- Arizona Fall League action concluded this week, with several players in Oakland's organization posting impressive results.

Top outfield prospect Michael Choice, the club's No. 1 pick in the 2010 Draft, finished with a .318 average, six home runs and 18 RBIs -- along with a 1.090 OPS -- in 66 at-bats spanning 17 games for the Phoenix Desert Dogs.

Leading the team in at-bats was fellow outfield prospect Grant Green with 107. He posted a .290 average with five homers, nine doubles and 19 RBIs while also progressing in his transition from shortstop to center field.

On the mound, right-hander Tyson Ross made seven starts, going 1-3 with a 5.94 ERA. Reliever Andrew Carignan, who, like Ross, spent time in Oakland this year, made 12 appearances, compiling a 6.57 ERA while striking out 16 in 12 1/3 innings.

A handful of other A's players are still in action in the Caribbean Winter Leagues, including first baseman Brandon Allen and pitchers Fautino De Los Santos, Graham Godfrey and Jordan Norberto.

A's add prospect Mitchell to 40-man roster

OAKLAND -- On the final day for clubs to set their 40-man roster, the A's on Friday added outfield prospect Jermaine Mitchell and elected to outright right-hander Evan Scribner and outfielder Cedric Hunter to Triple-A Sacramento.

By placing Mitchell on the 40-man roster, the A's have protected him from the Rule 5 Draft, to be held Dec. 8 at the Winter Meetings in Dallas. The move also ensures Mitchell of his first invite to big league camp.

Mitchell enjoyed a breakout 2011 season in the A's organization, batting .355 at Double-A Midland before earning a July 3 promotion to Sacramento, where he posted a .302 average with 14 doubles, three triples, five home runs, 28 RBIs and 13 stolen bases in 56 games.

The 27-year-old outfielder, a former fifth-round Draft pick by the A's in 2006, recently underwent knee surgery and likely won't be ready by season's start, but it's likely he'll play a prominent role in Oakland's outfield mix once healthy.

Scribner and Hunter were both claimed off waivers from San Diego on Oct. 25. Their departure from the 40-man roster, combined with the addition of Mitchell, leaves the A's with one open slot.