Vikings quarterback Matt Cassel will opt out of his team-friendly contract before Friday's deadline, according to NFL.com's Ian Rapoport. Cassel's deal would have been worth $3.7 million this season, but had the option to forgo the final season of a two-year, $7.4 million deal he signed last year wi­th the Vikings.

Calls to Cassel's agent, David Dunn, were not immediately returned.

The move makes sense for Cassel. It's a very thin free agency class for quarterbacks this offseason, headlined by Michael Vick, Josh McCown, Kellen Clemens and Josh Freeman, who spent the final 12 games of the season with the Vikings.

Cassel would climb, arguably, to the top of that free agent class as a serviceable quarterback looking for a multi-year deal. He'll likely get more money than he would've received if he decided to remain with the Vikings under his current contract.

Of course, Cassel could also re-sign with the Vikings for more money after free agency opens March 11. At the moment, Christian Ponder is the only quarterback on the Vikings' roster.

Whether the Vikings can sign Cassel remains unknown given the demand at quarterback. Six of the top 11 teams in the NFL Draft need a quarterback. Given the free agency class and the uncertainly of how many rookie quarterbacks would be ready to start immediately, Cassel could be looked at as a starting short-term quarterback for a franchise that seeks to develop its future quarterback through the draft.

If Cassel didn't opt out of his deal, the Vikings would owe him a $500,000 roster bonus (which is part of the $3.7 million) if he is still on the team a week after the official league season begins March 11.

Cassel, 31, played in nine games for the Vikings this season, starting six. He was 25th in the NFL in passer rating (81.6). Cassel started Week 4 against Pittsburgh in London when Christian Ponder was injured and led the Vikings to their first victory. Freeman was signed the following (bye) week, and Cassel struggled in a loss to Carolina. He returned to backup status, replacing Ponder in three games, twice because of injury. In Week 13, he beat Chicago after replacing an injured Ponder in the second half, and claimed the starting job with a strong performance in a loss at Baltimore the following week. In a Dec. 15. victory over Philadelphia, he had the best performance by a Vikings QB this season — 26-for-35 for 382 yards and two TDs. His passer rating of 90.7 was 13th in the NFL at that time, but fell after a loss to Cincinnati and a season-ending victory over Detroit.

Ponder, the 12th overall pick in the 2011 draft, signed a four-year contract for $10.15 million that is fully guaranteed. His signing bonus of $5.8 million is paid out evenly over the four years. For 2014, his salary is $1.76 million with another bonus of nearly $1.5 million. If the Vikings cut him this offseason, they would be on the hook for that money and a $3.2 million salary cap hit.

Cassel's career has been full of ups and downs. He was a backup to Heisman winners Matt Leinart and Carson Palmer at USC, and is the only modern-era quarterback who never started a college game to have started an NFL game.

The Patriots drafted Cassel in the seventh round (230th overall) of the 2005 draft, and he was a backup to Tom Brady for four seasons in New England. In 2008, Brady suffered a season-ending knee injury in the first game, and Cassel played the rest of the season, leading the Patriots to an 11-5 record. With his four-year contract expiring, the Patriots gave him the franchise tag early in 2009 and traded him to Kansas City for linebacker Mike Vrabel and a second-round draft choice.

Cassel's big season with the Patriots paid off. The Chiefs signed him to a six-year, $63 million contract that included $28 million in guaranteed money. He started in 2009, and in 2010 made the Pro Bowl as Kansas City won the AFC West. He injured his hand after 10 games in 2011, however, and after starting in 2012 he eventually lost his job to Brady Quinn.

Cassel was released last March, and the Vikings quickly signed him to back up Ponder. Here's Mark Craig's feature story on Ponder, written before last season.