OAKLAND -- The A's entered Thursday's four-game series opener against the Rangers looking to hold Texas' magic number at six, but they'll have to do so without relievers Jerry Blevins and Michael Wuertz. Both relievers were deemed unavailable by manager Bob Geren before the start of Thursday's contest due to bouts with injuries. Blevins is still nursing a strained left shoulder and hasn't thrown in a few days. Wuertz, meanwhile, is battling a sore right thumb but is at least throwing and could potentially return this weekend. Blevins and Wuertz have combined for 87 1/3 innings this season, and their unavailability will likely mean the club will rely on lefty Craig Breslow in the closer's role for most of the next four days. Breslow has racked up the most innings among all A's relievers, having tallied 69 1/3 innings with 11 games still remaining.