Pool of quality QBs extremely shallow

Peyton Manning and Tom Brady will go down in NFL history as two of the greatest quarterbacks the league has ever known.

If only the NFL had a few more of them to spread around.

The league has expanded faster than the supply of elite or even competent quarterbacks.

The first quarterback drafted in 1987 (Vinny Testaverde) started more games last season (6) than the first quarterback drafted in 2007 (JaMarcus Russell) (1).

In all, an NFL-record 64 quarterbacks started regular-season games in 2007. That number was up from 50 starters in 2006. Even if the number stabilizes in 2008, injuries will again force some teams to dig deep for stopgap solutions at the most important position.

General managers aren't likely to find appealing options when they get to their second and third reads.

The current crop of unrestricted free agents goes seven deep: Testaverde, Daunte Culpepper, Tim Hasselbeck, Tim Rattay, Jamie Martin, Craig Nall and Chris Weinke. Of them, Culpepper provides the best combination of age (31) and experience (90 regular-season starts). But he has thrown seven more interceptions (20) than touchdown passes (13) since suffering a catastrophic knee injury midway through the 2005 season with Minnesota.

Given a choice between Culpepper and Russell last season, the Oakland Raiders went with Josh McCown.

Another wave of quarterbacks will become available in September when teams reduce rosters to 53 players. That sounds promising in theory, but in reality, nearly all of them will be undrafted rookies or unaccomplished veterans. A damaged former starter or two could hit the market -- Tampa Bay's Chris Simms comes to mind -- but they will carry their own sets of risks.

GMs looking to the Arena Football League for the next Kurt Warner will have to pick him out of a lineup featuring current AFL passing leaders Matt D'Orazio, Joe Germaine, Russ Michna, Tony Graziani, Chris Greisen, Aaron Garcia, Raymond Philyaw, Matt Nagy, Shane Stafford and, well, best of luck to ya.

The pool of proven NFL quarterbacks is shrinking.

Brett Favre and Steve McNair are joining Testaverde in retirement. Another retired former starter, Jake Plummer, has shown no interest in resuming his career. Drew Bledsoe also has passed up chances to come back.

Of the seven unrestricted free agents, only Testaverde and Culpepper started games last season. Three other available quarterbacks -- Trent Dilfer, Kelly Holcomb and Byron Leftwich -- also made starting appearances. But none was brought back by the team that knew him best.

Leftwich has name recognition, but injuries make him a risky bet. He has appeared in fewer games each season since entering the league in 2003 (15, 14, 11, 6 and 3).

Rattay and free agent Aaron Brooks started games in 2006 but not last season. Free agents Mike McMahon, Cody Pickett and Matt Mauck started games in 2005. Jay Fiedler, 36, last started a game in 2004.

Testaverde was 43 years old when the Carolina Panthers, desperate after losing starter Jake Delhomme, revived his career in October. Testaverde started six games, and the Panthers won two of them.

As bad as the situation was for Carolina, which finished with a 7-9 record for the sixth time in its 13-season history, in some ways the NFL had it worse.

Testaverde's six starts exceeded the 2007 totals for 12 of the 28 quarterbacks selected in first rounds in the previous 10 drafts. Russell, Brady Quinn, Matt Leinart, Aaron Rodgers, Leftwich, David Carr, Patrick Ramsey, Michael Vick, Tim Couch, Akili Smith, Cade McNown and Ryan Leaf combined for 12 starts last season. Two other candidates, Alex Smith and Rex Grossman, each beat Testaverde by only one start. Another, Culpepper, matched him with six.
Quarterback injuries hit the Panthers, St. Louis Rams and San Francisco 49ers particularly hard last season.

Carolina is relying on a healthy Delhomme this season. The team also likes backup Matt Moore, who started three games last season. But the Panthers could sink again if Delhomme suffers another injury. Carolina is the only team in the league without a drafted quarterback. The Panthers have selected five in their history, and only one -- Kerry Collins, now with Tennessee -- went in the first three rounds.

The Rams added Trent Green to back up Marc Bulger. Green knows the system brought in by new offensive coordinator Al Saunders. He has Pro Bowl talent. But if the Rams cannot keep Bulger healthy, what are the odds of the nearly 38-year-old Green's finishing the season? He hasn't made it through one healthy since 2005.

The 49ers aren't sure whether Alex Smith is the answer. And if he's not? Backups Shaun Hill and J.T. O'Sullivan own two starts in a combined 14 NFL seasons. San Francisco remains thin at offensive tackle, the most important position for ensuring quarterback health, and new offensive coordinator Mike Martz asks plenty of his pass protectors.

Other teams could be at least as vulnerable when injuries strike. There simply aren't enough good quarterbacks to go around.

Testaverde turned 44 in November. As hard as it might be to envision his playing past 45, GMs seeking experienced help at the position might have a harder time coming up with superior alternatives.

Mike Sando covers the NFL for ESPN.com.