Crowder, a six-year starter in Miami, was released Friday following the first practice of training camp to pave the way for Burnett's acquisition.
Burnett played for the San Diego Chargers the past two seasons. He started seven games in 2009 and all 16 games last year, when he had 80 tackles, six sacks and two interceptions.
"I have a good history with Kevin," said Dolphins coach Tony Sparano, a former Cowboys assistant coach. "I was there with him in Dallas when we drafted him. This is a guy who can play on all three downs and runs really well and can cover some of the bigger tight ends and bigger backs in our league."
Replacing Crowder with Burnett gives the Dolphins more flexibility and better pass coverage, Sparano said. Even so, cutting Crowder wasn't easy.
"It was one of the toughest things I've ever had to do," Sparano said. "It's not the fun part of my job. Channing has been a pretty special player to me."
Copyright 2011 by The Associated Press