The last two quarterbacks to take the Broncos as far as the AFC Championship Game were free-agent pickups. So, yes, theoretically, you can find a franchise QB from free agency.

But Peyton Manning's availability in 2012 resulted from a confluence of circumstances unlikely to be repeated -- mid-30s quarterback out for a season in which his team collapsed to the point where it could take the best quarterback prospect in 14 years (since Manning himself).

And 2003, when Jake Plummer was available, was a different time and place; in that decade, you had viable quarterbacks pop onto the market: Plummer, Jake Delhomme in 2003, Drew Brees in 2006, to name some examples of quarterbacks who would become Pro Bowlers after joining their teams as free agents.

For teams studying the market this month, Manning, Brees or even Delhomme aren't walking through that door. But quality backups who can provide stability -- or push a younger, developing quarterback -- are available.

UNRESTRICTED FREE AGENTS:

MARK SANCHEZ, PHILADELPHIA:Having guided the Jets to back-to-back AFC Championship Games, Sanchez has some significant team accomplishments, and last year had his best individual season working in Chip Kelly's offense, although he was still marred by the inconsistency that has defined his career to date.

BRIAN HOYER, CLEVELAND:The Browns' addition of ex-Tampa Bay QB Josh McCown put the writing on the wall for Hoyer, who admitted Friday to USA Today that it is "good for both sides to get a fresh start." But Hoyer turns 30 in October, and is running out of chances to make an impression for anything beyond steady backup.

JAKE LOCKER, TENNESSEE:Shrouded in questions about his ability to avoid injuries and his sub-optimal accuracy -- which are at least tangentially connected -- he still has untapped potential and could be a buy-low option for a team that can give him a year or two to break some bad habits.

SHAUN HILL, ST. LOUIS:If the Rams had not dawdled in getting him back into the lineup, they might have made a playoff push. Instead, the brief resurgence that began with the Rams' thumping of the Broncos was too little, too late. Hill finished the season with a completion percentage of 63.3 percent and an 83.9 rating. At 35, he still has backup value and can keep a team afloat for a month or two until the starter returns.

MATT MOORE, MIAMI:Over three years have passed since Moore's last start, before the Dolphins drafted Ryan Tannehill in 2012's first round. He started 22 games for Carolina and Miami from 2009-11, and in that span, had a 29-to-22 touchdown-to-interception ratio and posted an 81.7 quarterback rating -- good, but not great, but under some adverse circumstances, particularly his five Panthers starts in 2010.

COLT McCOY, WASHINGTON:His flashes of brilliance -- and a 96.4 rating in five games, including four starts -- won't be enough to compel Washington to bring him back behind Robert Griffin III and Kirk Cousins, but the 28-year-old still has some intriguing upside and electricity to his play, even if it is inconsistent.

RYAN MALLETT, HOUSTON:He finally got his starting chance last November, and the results were mixed: a solid performance against Cleveland and a bad game against Cincinnati in which he completed just 46.7 percent of his passes. Staying with the Texans would be the best possible outcome for Mallett, but will that happen?

OTHERS OF NOTE:

Michael Vick, N.Y. Jets
T.J. Yates, Atlanta
Tyrod Taylor, Baltimore
Christian Ponder, Minnesota
Jason Campbell, Cincinnati
Luke McCown, New Orleans
Matt Flynn, Green Bay
Tarvaris Jackson, Seattle
Thad Lewis, Houston
Matt Hasselbeck, Indianapolis
Jimmy Clausen, Chicago
Josh Johnson, San Francisco
Joe Webb, Carolina
Scott Tolzien, Green Bay
Blaine Gabbert, San Francisco
Dan Orlovsky, Detroit

RESTRICTED/EXCLUSIVE-RIGHTS FREE AGENTS:

Austin Davis, St. Louis
Case Keenum, Houston
Ryan Lindley, Arizona
Kellen Moore, Detroit