the midst of an injury-filled season with the Avalanche, Calgary re-acquired McAmmond from Colorado on March 11, 2003 for a fifth-round selection in the 2003 NHL Entry Draft. McAmmond, however, couldn't play a game for the Flames for the rest of the season since the deal violated a rule at the time prohibiting teams from trading a player prior to the waiver draft and reacquiring them later in the year. McAmmond suffered another setback during the 2003–04 season with Calgary, sustaining a back injury and missing the remaining 13 games of the regular season and every game of the 2004 Stanley Cup Playoffs during Calgary's run to game seven of the 2004 Stanley Cup Final. Later years During the 2004–05 NHL lockout, McAmmond played for the American Hockey League's Albany River Rats, leading the team in scoring with 61 points (19 goals, 42 assists) in 79 games. When NHL play resumed, and as an unrestricted free agent, McAmmond signed a contract to play with the St. Louis Blues for the 2005-2006 season, where he tallied 15 goals and 37 points in 78 games. Following the season, McAmmond, again a free agent signed with the Ottawa Senators 2006-2007 NHL season. In Ottawa, McAmmond emerged as a dependable role player on a skilled Senator team. In the 2007 Senators Super Skills competition, McAmmond led the Senators as the fastest skater, and later, on March 30, 2007, he played his 800th career NHL game in a winning effort against the Montreal Canadiens. McAmmond recorded a Gordie Howe hat trick on April 15, 2007, in a playoff game against the Pittsburgh Penguins, scoring a goal, adding an assist, and winning a fight with Pittsburgh's Maxime Talbot. The Senators rolled into the 2007 Stanley Cup Final, only to lose the series in five games to the Anaheim Ducks. In game three, after scoring what turned out to be the game-winning goal (and the only win in the series) for Ottawa, McAmmond was the victim of a controversial elbow to the head from defenceman Chris Pronger. He left the ice with assistance and did not return for games four or five, suffering from a concussion. Just a few months after re-signing a multi-year contract with Ottawa, McAmmond suffered another concussion during a preseason game on September 25, 2007 from a hit to the head by Philadelphia's Steve Downie. McAmmond, knocked unconscious by the hit, was carried