As a senior, he was a two-way player at outside linebacker and wide receiver, while tallying 31 receptions for 571 yards and 5 touchdowns. He also practiced basketball.
As a redshirt freshman in 1993, he was a backup, playing in 9 games and making 18 tackles (10 solo). As a sophomore, he became a starter, registering 39 tackles (27 solo), 3 sacks (led the team) and 8 tackles for loss (led the team).
As a junior, he started 10 out of 11 games at outside linebacker, recording 47 tackles (38 solo) and 5 sacks. He also lined up at tight end in several games.
As a senior, he started 9 games, while making 40 tackles (33 solo) and being named to the AD's Honor Roll for the fifth consecutive semester. He finished his college career with 108 tackles and 12 sacks.
On December 2, 1997, he was signed as a free agent by the Philadelphia Eagles. On September 5, 1999, he was placed on the injured reserve list with a fractured and dislocated ankle.[5] He was released on August 28, 2000.[6]
In 2002, he was a backup defensive end behind Julius Peppers and Mike Rucker. In 2003, he had 38 tackles, 5 sacks, 9 quarterback hurries, 5 passes defensed and 2 interceptions, while playing in Super Bowl XXXVIII. He also played a key role on a special teams unit that blocked 5 kicks in the first 2 games of the season.
Wallace, along with fellow Maryland alumni Kris Jenkins, Peppers, Rucker and Brentson Buckner established a formidable defensive line rotation from 2002 to 2006, which many experts considered to be among the best during that time span.
In 2006, he registered 30 tackles, 3 sacks and 13 quarterback hurries. On February 19, 2007, he was released because of salary cap reasons.[9] He appeared for the Panthers in 80 regular season games and 7 postseason contests, while never missing a game.
On August 22, 2007, he was signed as a free agent by the Buffalo Bills, for depth purposes behind Aaron Schobel and Chris Kelsay.[10][11] On September 1, he was placed on the injured reserve list.[12] He wasn't re-signed after the season. During his career he played in 96 games, posting 187 tackles (126 solo), 23 sacks and 4 interceptions.