Since Brent Rooker landed on the injured list (IL) on April 10, Carlos Cortes has been one of the A's most dangerous hitters, batting .333 with a 184 wRC+ (100 is league average) out of the DH spot, while adding four home runs and striking out just 6.7% of the time. Brent Rooker has been out of action with an oblique strain, and that injury is always tough because an oblique can take a player out for a couple of weeks, or a couple of months. This weekend in Arlington, Texas, A's manager Mark Kotsay made it seem as though Rooker's bat could be back in the lineup in short order. "For Rook, he's really close. The progression has gone really well. He'll take batting practice [Friday]. He's already hit off a velo machine.…