The Flyers first sent Calder, an unrestricted free agent July 1, to Chicago for a 2007 third-round draft pick and Lasse Kukkonen. The Hawks then flipped Calder to the Wings for winger Jason Williams.
Calder was a big disappointment in his first season with the Flyers, scoring only nine goals and 21 points in 59 games. Calder had 26 goals and 33 assists in 79 regular-season games for the Blackhawks last season, leading the team in goals, assists, points and game-winning goals.
"With Kyle's pending unrestricted free agent status coming up, we did make an attempt to sign him, but it didn't look like we were going to get it done before the trade deadline," Flyers general manager Paul Holmgren said. "We just felt that we couldn't afford to take a chance and get nothing in return for an asset like Kyle. We did what we needed to do."
Kukkonen has five goals and 14 points in 54 games for the Blackhawks this season. He was second on the team in blocked shots with 98. Over parts of two seasons with Chicago, Kukkonen has five goals and 10 assists for 15 points in 64 regular season games.
Williams had 11 goals and 15 assists in 58 games with the Red Wings this season. For his career, he has 49 goals and 67 assists in 233 games.
"We've been trying to acquire Jason Williams since last summer," Blackhawks GM Dale Tallon said in a statement. "He is a quality individual who can add to our team offensively and can also play the point on the power play. We feel with his speed and skill he is another piece of the puzzle as we continue to move forward in making our team better."