Brent Alexander came to the Steelers from Carolina, as an unrestricted free agent in 2000. The Steelers were in need of a savvy signal-caller for the secondary and Alexander fit the role to a tee and has been the starting free safety since the start of that 2000 season. After being awarded a 3-year contract extension just prior to the start of the 2001 season, Alexander posted a career-high 4 interceptions.

Brent was originally a 1994 undrafted free agent of the Cardinals and started 7 games as a cornerback his rookie season. During the 1995 and 1996 seasons with the Cardinals, he started mainly at free safety but filled in at strong safety and cornerback when called upon - 71 tackles and 2 interceptions in 1995, and 105 tackles and 2 interceptions in 1996. Alexander was the starting free safety for Arizona in 1997 and garnered 109 tackles in 15 starts. Brent moved on to Carolina in 1998 and started 11 games at free safety and 5 at strong safety, finishing the season with 114 tackles and a dramatic forced fumble during a goal-line stand against Miami.

In 1999, Alexander started the entire season at strong safety for the Panthers, with 96 tackles, two interceptions, 8 passes defenced, a quarterback hurry, and seven special teams tackles.

A walk-on at Tennessee State, Alexander was an NCAA I-AA All-American his senior year. In 3 years at Tennessee State, he had 285 tackles and 15 interceptions.