Athletics manager Mark Kotsay recently told reporters that the team’s second baseman, Zack Gelof, could be making his long-awaited season debut this weekend against the San Francisco Giants. Late in camp he injured his hamate and needed surgery, and on the rehab assignment from that injury ended up with a stress reaction in his ribs that prolonged his time on the IL. Gelof has been on his current rehab assignment since June 17 down in Triple-A Las Vegas, as the club was giving him a full spring training’s worth of at-bats to get him ready. After playing in Wednesday’s game with Vegas, Gelof has racked up a total of 34 at-bats, going 9-for-34, good for a .265 batting average.