A second-round pick (No. 55) by the Columbus Blue Jackets in 2005, McQuaid has 66 points (13 goals, 53 assists) in 462 NHL games, all with Boston, and won the Stanley Cup in 2011. He has 11 points (three goals, eight assists) in 68 playoff games.
"It's tough to see him go ... 10 years we've been together, going back to Providence (in the American Hockey League)," Bruins coach Bruce Cassidy said. "Today was a tough morning ... we'll miss him."
Kampfer, who turns 30 on Sept. 24, had one assist in 22 games for the Rangers last season. A fourth-round pick (No. 93) by the Anaheim Ducks in the 2007 NHL Draft, he has 26 points (10 goals, 16 assists) in 166 games with the Bruins, Minnesota Wild, Florida Panthers and Rangers.