After his senior season at Auburn, Whitehead started his pro career in 1995 after being signed as a free agent with the Baltimore Stallions in the Canadian Football League. That was followed by brief stints with the 49ers (1995) and Montreal Alouettes (1996). After being released by Montreal, he attended an ELITE Regional Combine in March of 1997 to assist his efforts of continuing his pro career. He performed very well and landed back in the CFL in 1997 with the Hamilton Tiger-Cats. He left for the NFL in 1998, signing with the Detroit Lions. Later released by the Lions, he signed with the Saints in February 1999.
In 2003, Willie appeared in 11 games, made 10 starts and posted a career-high 53 tackles, 5.5 sacks for minus 33 yards, a pass defensed, a forced fumble and a fumble recovery.
A six-year NFL veteran, Willie provides a quality, proven player to the defensive line rotation at both end and tackle. When healthy he has been among the Saints most consistent defensive performers. Since joining the team in 1999, Willie has started 25 of 68 games, with 178 tackles (122 solo), 23 sacks for minus-147 yards, three forced fumbles, two passes defensed and a fumble recovery.
