Kolb, 28, was a second-round selection of the Philadelphia Eagles in the 2007 NFL Draft. He started in just seven games over four seasons before he was traded to the Cardinals in 2011, in exchange for cornerback Dominique Rodgers-Cromartie and a second-round pick in the 2012 NFL Draft. Arizona promptly gave him a six-year deal worth $65 million, which he never lived up to.
However, in his final season with the team he showed plenty of positive signs, helping to lead the Cardinals to a 4-0 start before injuring his ribs in Week 6, ending his season. He finished the year with eight touchdowns, three interceptions and an 86.1 passer rating, more than 30.0 higher than any other Cardinals quarterback in 2012.
The Bills finished with a 6-10 record in 2012 before releasing quarterback Ryan Fitzpatrick. Similar to the Cardinals' deal with Kolb, Buffalo gave Fitzpatrick a six-year, $59 million deal that didn't work out for the team and ended with Fitzpatrick's release earlier in the 2013 offseason.
Buffalo finished the 2012 season with the league's 25th-ranked passing offense.