Brett Anderson has reached the end of his 30-day rehab assignment and must return to the A's by Monday, according to the San Francisco Chronicle's Susan Slusser.
Manager Bob Melvin was "impressed" with a recent bullpen session by Anderson, who is 1-1 with a 4.97 ERA in six minor league starts. Recovering from left elbow surgery, Anderson's last major-league start came on June 5, 2011.
If Anderson does join the A's rotation, he could take the spot of one of three rookies: Dan Straily, Tommy Milone or Jarrod Parker.
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