Backup QB Breakdown

Posted by ESPN.com's Paul Kuharsky

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Houston: If Matt Schaub is unavailable, the Texans' situation is shaky.Head coach Gary Kubiak and offensive coordinator Kyle Shanahan like a lot of things about Dan Orlovsky, but the newcomer who was signed to replace Sage Rosenfels is still learning the offense and breaking old habits. He'll get better as the season moves along, but if they need him to play early on, there will be a significant drop off. Rex Grossman is also on the roster, but has missed most of the preseason with a hamstring injury. The team was never picturing him as a No. 2 candidate, and if he sticks it will be as the third -- which would make a change in philosophy for a team that usually keeps only two.

Indianapolis: If Peyton Manning is unavailable, the Colts' situation is potentially disastrous.No player in the league ranks as more indispensable than Manning, who's started all 16 games in 11 consecutive seasons. The backup is Jim Sorgi, who missed much of the preseason with a hamstring injury. Recently head coach Jim Caldwell emphasized Sorgi's hold on the No. 2 spot. He's played in 14 games as a quarterback over five seasons, posting an 89.9 passer rating, but that came in mop-up work or late-season games when the Colts had their playoff position sealed up.

The Colts spent a sixth-round pick on Curtis Painter. It will be difficult for the Colts to go three deep at a position where they never expect to need the second guy, so the plan might be to develop Painter on the practice squad. But another team could alter that plan.

Jacksonville: If David Garrard is unavailable, the Jaguars' situation is really bad. Garrard is looking to establish himself as the long-term solution at the position.One thing he is not facing is pressure from behind, where Todd Bouman is currently the backup. Bouman's been in the league for 12 seasons, including some time with Jacksonville in 2007, and has played in 42 games with six starts. He's thrown 11 touchdowns and 11 interceptions, but has not been on the field in the regular season since 2005, when he had a 54.7 passer rating in 16 games and three starts for the New Orleans. Reports say the team recently inquired about Kansas City's Tyler Thigpen. Odds are they bring in someone to replace or at least challenge Bouman before the season starts.

Tennessee: If Kerry Collins is unavailable, the Titans' situation is hard to predict. Vince Young is the backup.If he comes into a game to replace an injured Collins, he can change the dynamic and make things difficult on a defense. But if he's slated to start games, the league has shown he can be well defended by complicating coverages and hemming him in to keep him from running. While Collins is a pocket passer, standing in and running through reads isn't Young's strength. If the Titans turned to him, they'd be wise to alter the plan to allow him to do more of what he's good at, with rollouts, quick and simple decisions and opportunities on the move. Offensive coordinator Mike Heimerdinger likes the third quarterback, Patrick Ramsey, a lot. Tennessee could carry three.