Leaf was the second overall pick in the 1998 draft by the San Diego Chargers, but never came close to living up to expectations and was a bust before his release in February, 2001. He endured two injury-plagued seasons and often feuded with management.
The Tampa Bay Buccaneers signed Leaf last summer before cutting him before the season.
Leaf was signed by the Cowboys in October after Carter tore his hamstring. Leaf lost all three of his starts for Dallas and completed 45-of-88 pssses in four games. His best effort was in a Thanksgiving Day loss to Denver in which the Cowboys rallied from a 26-3 deficit before losing 26-24.
A collegiate star at Washington State, Leaf is 4-17 as an NFL starter with 14 touchdown passes and 36 interceptions.