In June 2006 Auld was involved in a multi-player trade that sent him, Todd Bertuzzi, and Bryan Allen to Florida for Roberto Luongo and Lukas Krajicek, and a sixth round draft pick. Initially, Auld was expected to be the undisputed starter in Florida. However, the July 25 signing of Ed Belfour introduced some competition, and Belfour eventually won the job as starting goalie. In October, Auld was hospitalized while "horsing around" with Belfour, leading some to believe that Belfour had assaulted him.

 

On August 13, 2007, Auld signed a one-year contract with the Phoenix Coyotes, where he competed for a job with David Aebischer and Mikael Tellqvist. After briefly carrying three goaltenders, the Coyotes waived Aebischer and assigned him to the minors. Through November, Auld had received the majority of the starts in Phoenix.

 

On November 11, 2007, Auld allowed San Jose forward Jeremy Roenick's 500th career goal in the 2nd period.

 

On December 6, 2007, Auld was traded to the Boston Bruins for right winger Nate DiCasmirro and the Bruins' 5th round pick in the 2009 NHL Entry Draft.

 

On December 8, 2007, in his first appearance as a Bruins goaltender, he repeated his feat of making his first appearance with a new team, also being his first win, backstopping the Bruins to a 2-1 road game victory against the Toronto Maple Leafs. Only one week later, on December 15, Auld achieved his first shutout for the Bruins, backstopping his team to a 2-0 home game defeat of the Columbus Blue Jackets.