Jacksonville Jaguars quarterback Luke McCown appears to have a torn ACL in his right knee, Jaguars head coach Jack Del Rio said on Monday.

McCown replaced starter David Garrard in the second half of Sunday's 38-13 loss to the San Diego Chargers, completing 11-of-19 passes for 120 yards before injuring the knee in the game's final minute.

McCown tore the same ligament in 2006.

The only other quarterback the Jaguars have under any contract is Brett Ratliff, who was signed to the practice squad in September after being waived by the Cleveland Browns earlier this month. With McCown likely out for the rest of the season, the Jaguars will be in the market for a veteran back-up quarterback to play behind Garrard.