Jaguars backup QB Luke McCown will undergo an MRI today on his right knee after taking a hit in the fourth quarter of the team's Week Two loss at San Diego, according to the Florida Times-Union.

McCown, who replaced the ineffective David Garrard during the final quarter of the game, was 11-for-20 for 120 yards. He scrambled down to the Chargers' 3-yard line before falling hard on his knee with less than a minute to go. Garrard then returned to the game and threw a TD pass.

The team does not have a third QB on the roster, although third-year pro Brett Ratliff is on the practice squad.

The way we see it

Losing a backup QB always hurts, especially when the starter throws four interceptions in a 38-13 defeat. McCown, a seven-year vet, is a solid backup whom the team will need to replace if the knee injury is serious.