EDEN PRAIRIE, Minn. — The Vikings on Wednesday announced they have agreed to trade quarterback Matt Cassel to the Bills for an undisclosed draft pick.

The deal will not be finalized until the NFL's 2015 year begins at 3 p.m. (C.T.) on March 10.

Cassel is at the onset of his 11th NFL season. He arrived in Minnesota in 2013, appearing in nine games that season. Cassel was selected in 2014 by first-year Head Coach Mike Zimmer to be the Vikings starter after a competition in training camp.

Cassel led the Vikings to victory in the season-opener at St. Louis but was unable to replicate results the following week at home against New England, the team that originally drafted him in 2005. Cassel backed up Tom Brady his first three seasons and went 10-5 in replacing Brady in 2008. He was traded to Kansas City in 2009 and was selected to the Pro Bowl after throwing a career-high 27 TDs in 2010. He was released by the Chiefs in 2013 and joined the Vikings.

After winning the starting job last year in camp, Cassel suffered a season-ending foot injury in Week 3 that required surgery and extensive rehab. The veteran stayed positive and frequently helped develop his replacement, Teddy Bridgewater, who set multiple franchise records by a rookie quarterback.

Bridgewater's six wins in 12 starts, 64.4 completion percentage and 85.2 passer rating were all records for a Vikings rookie, and gave coaches and the personnel department the belief he will be the starter to build around for years to come.

Media reports have predicted that Vikings quarterback Christian Ponder will become a free agent next week, which would leave Pat Devlin, who joined the team in November, as the only other QB on Minnesota's roster.

The Vikings said during the NFL Scouting Combine that they have interest in drafting or signing a player to develop at the position but could also take a look at other veteran QBs that are expected to hit the market.