In his first year, he had some success with 355 yards on 84 carries, but was only used sparingly in his last three years due to decisions made by former head coach John Bunting to restrict Parker's playing time until he "bulked up" to fit within Bunting's attempt at establishing a power running game.
Willies best game was the Peach Bowl against Auburn where he racked up 131 rushing yards on 19 carries and scored one touchdown.
While at UNC, Parker displayed great speed, but little vision, resulting in inconsistent play which led to him being benched in favor of Ronnie McGill during his senior year.
Parker's experience as a backup in college drew comparison to Hall of Famer Franco Harris, the Steelers all-time leading rusher and Super Bowl IX MVP, who served as a backup to Lydell Mitchell when he played at Penn State, as supposedly, head coach Joe Paterno preferred Mitchell's style over Harris'.
He spent the 2004 NFL season as a backup player behind Jerome Bettis, Duce Staley and Verron Haynes.
In his second year, Parker earned the starting job after both Bettis (hamstring) and Staley (knees) missed the first part of the season with injuries.
He impressed Bill Cowher, as well as Titans coach Jeff Fisher, by gaining 161 rushing yards on 22 attempts (7.3 average).
After following this performance with another 100+ yard game against the Houston Texans, Cowher gave Parker the starting position.
The previous longest was 74 yards by Marcus Allen in Super Bowl XVIII against the Washington Redskins.
In 2006, Parker signed a major contract with the Steelers, a four-year $13.6 million deal that would solidify his future role on the team.
In addition, his 16 combined scores broke the previous Steelers single-season touchdown mark of 15 set by Louis Lipps in 1987.
Parker served as a backup to LaDainian Tomlinson and Larry Johnson in his first Pro Bowl, where he would finish the game with 40 yards on 2 carries.
He had eight 100-yard plus games, leading the league in that category and earning a second consecutive Pro Bowl berth before being injured late in the season.
Parker suffered a broken right fibula early in a game against the St. Louis Rams on December 20, 2007, ending his season.
Coming off of his broken leg near the end of the 2007 campaign, there were questions surrounding Willie Parker's ability to recover.
In this game, Parker would record 138 rushing yards and a career-high 3 touchdowns, all before the fourth quarter ever started.
The third-string running back, Mewelde Moore, produced well in Parker's absence, with 908 yards from scrimmage.
In Super Bowl XLIII, Parker was not able to make a significant impact, as the Pittsburgh Steelers were unable to establish a strong rushing game.
Regardless, with Ben Roethlisberger at the helm establishing the passing game, the Steelers went on to collect their sixth championship ring in Super Bowl XLIII, becoming the first team in NFL history to obtain that amount.
Parker began his final contract year with the Steelers as the starter for the first three games of the season, carrying for 19, 47, and 93 yards.
[15] Beginning in 2015, Parker became running backs coach at Heritage High School in Wake Forest, North Carolina.