Engelberger was a Second-team All-American and a First-team All-Big East Conference choice following a senior season at Virginia Tech that saw him record 53 tackles (32 solo) and seven sacks.
The next season, 2002, Engelberger played 15 regular-season games (0 starts) and both postseason contests for San Francisco, compiling 12 tackles (11 solo) and one special-teams stop.
In 2004 Engelberger played 16 regular-season games (15 starts) at left defensive end for San Francisco, recording career highs in tackles (64) and sacks while matching his personal best with four forced fumbles.
In his first season with the Broncos, Engelberger played 14 regular-season games (0 starts) and contributed 24 tackles (17 solo) as a part of the NFL's second-best run defense (85.2 ypg).
In 2007 Engelberger led the Broncos’ defensive line with 59 tackles (40 solo), starting 15 of 16 games played and one sack, two pass breakups and one forced fumble.
He earned the team's nomination for the Ed Block Courage Award by starting its final 12 games despite suffering a fifth-degree separation of the AC joint in his right shoulder in Week 4.