By Madeline Coleman The quarterback fractured his thumb in the team’s season-opener and had surgery. Cowboys coach Mike McCarthy revealed during Wednesday’s media availability that Dak Prescott will be throwing on the side with the rehab group during practice. He will also throw to receivers at the end of practice, but Cooper Rush is being prepared to be the starting quarterback against the Eagles on Sunday. McCarthy still considers Prescott in the “medical, rehab phase.” This marks the quarterback’s first day of throwing since he fractured his thumb against the Buccaneers in September. Presco…