Gagne, 35, spent 11 of his 14 seasons playing with the Philadelphia Flyers. The Flyers selected him in the first round (22nd overall) of the 1998 NHL Entry Draft. The forward played in 691 games for the Flyers, where he scored 264 goals, had 271 assists, tallied 535 points and racked up 284 penalty minutes. He scored over 40 goals in back-to-back seasons, and they were the only seasons in which he registered over 40 goals. Gagne also has over 40 points in nine of his 14 seasons in the NHL.
Gagne led the Flyers in goals three separate seasons, and also led the team twice in points. He was a two-time All-Star (2001 & 2007). The forward won the Bobby Clarke Trophy as the Flyers Team Most Valuable Player on two separate occasions. Gagne ranks ninth on the Flyers all-time list in goals with 264 scored. He also ranks 10th in franchise history with 535 points and 691 games played. Gagne ranks fourth on the Flyers all-time list among left wingers in goals and in points.
Gagne scored some pretty memorable playoff goals during his time with the Flyers. In game six of the 2004 Eastern Conference Finals, he scored the game-winning goal in overtime to force a game seven against the Tampa Bay Lightning. The Lightning eventually went on to win game and the Stanley Cup.
He was also instrumental in helping the Flyers to come back from a 0-3 deficit against the Boston Bruins during the 2010 playoffs. Gagne scored the game-winning goal in overtime of game four, and he also added two more goals in game five. The Flyers went on to win game six to force an important game 7 in Boston. The Flyers quickly found themselves down 3-0 before the first period was even over, but they fought back to tie the game like they had the series. Gagne scored the game-winning goal in the third period for a 4-3 game and series win. The Flyers were only the third team to come back from an 0-3 series deficit to win the series.
He was traded to the Lightning in the summer of 2010 for Matt Walker and a conditional fourth round in the 2010 NHL Entry Draft. The Flyers selected Marcel Noebels in the fourth round. Gagne became a free agent in the summer and signed a two-year contract with the Los Angeles Kings, where he helped to lead the Kings to a Stanley Cup. In February 2013, Gagne was traded back to the Flyers. Gagne won a roster spot with the Bruins last season, but only played 23 games and registered four points.
Gagne missed good chunks of two seasons (2007-08 & 2011-12) due to concussions, but he still managed to put up good numbers despite the concussions.