Yes
A 6-foot-4, 228-pounder, Cassel started his career as a backup to Tom Brady with the Patriots. When Brady was hurt in the 2008 season opener, Cassel got his first extended playing time, going 10-5 as a starter and leading the Patriots to an 11-5 record (although they still missed the playoffs). Cassel went 327 of 516 (63.4 completion percentage) that season for 3,693 yards, 21 touchdowns and 11 interceptions. He played so well that the Patriots used their franchise tag on him, which would have guaranteed him a one-year salary of $14.65 million. Cassel never signed that, however, and was traded to Kansas City for a second-round draft pick. The Chiefs signed him to a six-year contract worth up to $63 million. Tom Brady went down and did not get up. It didn’t look good and the Patriots season seemed to be in peril only one quarter into the season. Brady hobbled off the field with a torn ACL and MCL. And he would be lost for the entire 2008 season. Inexperienced backup Matt Cassel entered the game to lead the Patriots. The same Matt Cassel who had a horrific preseason and barely survived preseason cuts. But Bill Belichick saw something in Cassel’s work ethic in practice to keep the seldom used signal caller around Backup quarterback Matt Cassel replaced Brady. Cassel's start in Week 2 was his first start in a game since high school, and he led the Patriots to a win, which extended the Pats' regular-season winning streak record to 21 games before a loss the next week ended the streak. This record was broken by the Indianapolis Colts in 2009. The 2008 New England Patriots season was the 37th season for the team in the National Football League and 49th season overall. Cassel spent his entire Trojan career as a backup behind Heisman Trophy winners Carson Palmer and Matt Leinart. Cassel was the backup for Palmer during his Heisman-winning 2002 season. In the fall, Cassel lost the battle for the starting position to the previous third-string quarterback in Leinart. Cassel was expected to compete with Tyler Thigpen, who started 11 games for the Chiefs in 2008, for the starting quarterback position. Since Cassel's number 16 from New England is retired in Kansas City in honor of Len Dawson, Cassel decided to wear number 7; he chose 7 because it equals one plus six. In the 16th game of this season Cassel made another huge leap in his Pro Football career. Cassel led the Patriots to a 47–7 blowout win through snow, sleet, and rain in the Patriots' last regular-season home game of 2008. In the wake of his performances against the Jets and the Cardinals (in the snow) and the uncertainty over Brady's recovery, NFL analysts and reporters have raised the question of whether the Patriots should, or will, apply the franchise tag to him. He became the Patriots' starting quarterback after Week 1 of the 2008 season after then reigning NFL MVP Tom Brady suffered a season-ending knee injury. According to ESPN research, he is the only known quarterback in NFL history to start an NFL game at quarterback without ever starting as quarterback in college. Cassel was expected to compete with Tyler Thigpen, who started 11 games for the Chiefs in 2008, for the starting quarterback position. Since Cassel's number 16 from New England is retired in Kansas City in honor of Len Dawson, Cassel decided to wear number 7; he chose 7 because it equals one plus six. As the season comes to an end, the New England Patriots are looking to make the playoffs. Matt Cassel, who took over the team this year due to an injured Tom Brady, has stepped up to the plate and hit a home run. When the year began, all eyes were on Tom Brady. Understandably so considering he is amazing on the field and gave the Patriots an undefeated season last year until the Super Bowl. In the wake of his performances against the Jets and the Cardinals (in the snow) and the uncertainty over Brady's recovery, NFL analysts and reporters have raised the question of whether the Patriots should, or will, apply the franchise tag to him. The day after the game, the Patriots confirmed that Brady's serious injuries would sideline him for the rest of the season. Although the Patriots did bring quarterbacks Chris Simms and Tim Rattay to Foxborough, they signed neither, and kept Cassel as the starter. Cassel was expected to compete with Tyler Thigpen, who started 11 games for the Chiefs in 2008, for the starting quarterback position. Since Cassel's number 16 from New England is retired in Kansas City in honor of Len Dawson, Cassel decided to wear number 7; he chose 7 because it equals one plus six. Miami qualified for the playoffs by winning the AFC East division over the Patriots on the fourth divisional tiebreaker (better conference record: 8–4 to 7–5). Baltimore qualified for the playoffs as a wild card team, defeating the Patriots on the second wild card tiebreaker (better conference record: 8–4 to 7–5). The 2008 New England Patriots season was the 37th season for the team in the National Football League and 49th season overall.
http://bills.buffalonews.com/2015/03/04/bills-swing-another-trade-will-acquire-quarterback-matt-cassel-vikings/ http://bleacherreport.com/articles/526747-fifty-years-of-patriots-football-2008-the-year-of-matt-cassel https://en.wikipedia.org/wiki/2008_New_England_Patriots_season https://en.wikipedia.org/wiki/Matt_Cassell http://bleacherreport.com/articles/96739-matt-cassels-future-part-ii-playoffs-raise-his-value-to-pats https://en.wikipedia.org/wiki/Matt_Cassell http://bleacherreport.com/articles/96739-matt-cassels-future-part-ii-playoffs-raise-his-value-to-pats https://en.wikipedia.org/wiki/Matt_Cassell https://en.wikipedia.org/wiki/2008_New_England_Patriots_season
did patriots make the playoffs with matt cassel