The 30-year-old running back was described by owner Jeffrey Lurie as "one of the more electric players in the history of our franchise and certainly one of the most popular."
Westbrook first made headlines at the collegiate level when the 19-year-old became the first player in NCAA history to record at least 1,000 rushing and receiving yards in the same season (1998).
He earned the Walter Payton Award as the top player in NCAA Division I-AA in 2001 and concluded his college career as the all-time leader in total yards from scrimmage.
Westbrook played sparingly throughout the 2002 season, but made his mark as a superstar with a fantastic 2003 season.
As one-third of the Eagles' powerful three-headed running attack, Westbrook rushed for seven touchdowns, caught four more, and returned two punts for touchdowns on just 174 touches.
Only six players in NFL history have ever accumulated at least two touchdowns rushing, receiving, and returning in the same season, and none of them scored double-digit touchdowns like Westbrook.
The signature play of Brian Westbrook's career came in the season's sixth game, when he returned a punt 84 yards for a touchdown in the final minute and a half of play against the New York Giants to snatch victory from the jaws of defeat.
Find an Eagles fan anywhere and he will fondly recall Merrill Reese's famous call:
"He gets it away, it's a wobbler. Bounces across the 20. Westbrook takes it, looks for running room. Up to the 25, the 30, to the 35, 40. 45, midfield. 45, 40. 35, 30. Brian Westbrook! He's going, he's gone! Touchdown! Brian Westbrook 84 yards! I don't believe it! Brian Westbrook has just exploded. This place is in a state of shock!"
The play is remembered as the Miracle at the Meadowlands II and propelled the Eagles on a nine-game winning streak.
In 2004, Westbrook became the team's starting running back after Duce Staley left the team and Correll Buckhalter suffered a preseason injury.
He rushed for 812 yards, caught 73 passes for 703 yards, and scored nine touchdowns, while earning Pro Bowl honors. He became just the third player in league history to surpass 700 yards both on the ground and through the air, with one or fewer fumbles.
In the postseason, Westbrook accumulated over 100 yards in all three games, as the Eagles advanced to their second Super Bowl in franchise history. In Super Bowl XXXIX, he caught a third-quarter touchdown from Donovan McNabb to tie the game at 14.
After an injury-plagued 2005 season, Westbrook turned in one of the greatest seasons by a running back in Eagles' history.
He rushed 240 times for 1,217 yards and seven touchdowns, while catching 77 passes for 699 yards and four touchdowns.
Against the Tampa Bay Buccaneers, Westbrook topped 100 yards rushing and receiving, just the 25th time a player has accomplished both feats in the same game. His 52-yard touchdown reception, in which he broke five tackles, gave the Eagles a 21-20 lead with just 33 seconds remaining in the game.
Three weeks later, against the Tennessee Titans, Westbrook became the sixth player to rush for 100 yards and catch 10 passes in the same game.
He rushed 20 times for an Eagles' postseason record 141 yards and a touchdown against the Giants in the wild-card round of the playoffs, including a breathtaking 49-yard touchdown run to tie the game in the second quarter.
Against the Saints in the divisional round, he rushed 13 times for 116 yards and two touchdowns, including a 64-yard touchdown run, the longest rush in Eagles' postseason history. Westbrook became just the seventh player to rush for 100 yards and a touchdown in consecutive postseason games.
In the 2007 season, Westbrook turned in arguably the greatest offensive season by an Eagles player since Steve Van Buren.
He earned All-Pro honors, as well as his second Pro Bowl season, by rushing for 1,333 yards and seven touchdowns, while catching a franchise-record 90 passes for 771 yards and five scores. He led the NFL with 2,104 yards from scrimmage and became just the fourth player in NFL history rush for at least 1,000 yards and catch 90 passes in the same season.
Westbrook's season included a slew of notable games.
And he famously took a knee at the one-yard line in the final two minutes against Dallas, allowing the clock to run out and preserving a huge upset win for the Eagles.
Westbrook's decline began during the 2008 season, although he did score 14 touchdowns.
He also rushed for a career-high 167 yards against the Falcons. Against the Arizona Cardinals, he became the first player since 1975 to accumulate 100 rushing yards, two touchdowns rushing, and two touchdowns receiving in the same game.
In the postseason, however, he was virtually nonexistent for three games, with the exception of one play. Against the Vikings in the wild-card round of the playoffs, the Eagles led 16-14 late in the fourth quarter before Westbrook scored on a 71-yard screen pass, sealing an Eagles' victory.
In the 2009 season, Westbrook started just seven games, suffering multiple concussions which forced him to miss the majority of the season.
He played sparingly in the final two games, both losses to the Dallas Cowboys, and his final touch as a member of the Philadelphia Eagles was a 27-yard reception.
Westbrook was released on Feb. 23.
The 30-year-old running back is the franchise's all-time leader in yards from scrimmage in a career (9,785) and a single season (2,104), and ranks third in touchdowns (68).
He was one of the two or three best running backs in the league during the 2006 and 2007 seasons, and was a top-10 back for the majority of his career.
Westbrook's versatility, notably his ability to run and receive, was unprecedented across the league, and it could be argued that no player in the NFL was better at holding onto the football than Westbrook.
Not a single running back in NFL history has more yards from scrimmage (9,785) with fewer fumbles than Brian Westbrook (12). And Westbrook's rate of one fumble every 144 touches is the best mark by a running back in NFL history (minimum 1,500 touches).
Westbrook has six months before the season begins if he wishes to sign with another team.
But I'll be honest. I hope that the Eagles' best offensive weapon of my lifetime never plays again. He doesn't belong anywhere but with the Philadelphia Eagles.