Getty Images The Dallas Cowboys are looking for a solid backup for Dak Prescott. The Dallas Cowboys feel good about where Dak Prescott is in his rehab but are not satisfied with the composition of their quarterback room and could turn to a trade to add depth. Prescott had surgery on his hamstring on Nov. 13 . The injury limited him to just eight games last season. “Dak’s doing great,” Cowboys executive vice president Stephen Jones said . “He’s very thrilled with where he is, and I know the