Ticketed for a redshirt year in 2002, he was activated nine games into the season due to a rash of injuries at the linebacker position, ultimately burning a year of eligibility to play in four of the five remaining games.
Mitchell played in all 12 regular-season games in 2003 but missed the Peach Bowl due to a knee injury. Knee surgeries in January and August caused him to miss the entire 2004 season. Limited by an assortment of nagging injuries, he started just two of Tennessee's 11 games in 2005.
Mitchell was arrested May 2, 2006 and charged with disorderly conduct at a campus-area convenience store. He bounced back from that setback, however, to have an excellent senior season, ultimately being voted a team captain.
Healthy for the first time in his career, he started all 13 games at middle linebacker last fall. After recording just 50 tackles in his first four years on campus, he led the 2006 Vols with 104 stops. He also paced the team in tackles for loss (10.5) and fumbles forced (2). He ranked second in quarterback hurries (11) and returned an interception 17 yards for the game's first touchdown at South Carolina.
Because of durability concerns, the 6-3, 249-pounder lasted until Round 7 of the recent NFL Draft before New Orleans called his name.
In announcing the signing of Mitchell, Saints Executive Vice President Mickey Loomis said: "Marvin is a strong young player and he's adapted well to our system through the minicamps and OTAs (organized team activities). He's a real competitor who will push hard for a spot in our linebacker corps during training camp."