ARLINGTON -- Rookie left-hander Martin Perez is scheduled to pitch on Monday against the Athletics in Oakland. But manager Ron Washington said Perez is in the bullpen this weekend against the Angels and will be used if needed. That would leave the Rangers undecided for Monday against the Athletics. "If we don't use him out of the bullpen this weekend, then he's the guy on Monday," Washington said. "But we've got to get through these two games and everybody is on deck." Right-handers Scott Feldman and Roy Oswalt are candidates to start on Monday if needed. But Oswalt hasn't thrown more than two innings or 50 pitches in a game since a start against the Twins on Aug. 23.