"Channing Crowder was discussing the prospects for the Dolphins' defense over lunch with fellow inside linebacker Karlos Dansby at the team practice facility Friday when he was told he was wanted upstairs.

A short time later, after meetings with General Manager Jeff Ireland and coach Tony Sparano, Crowder returned only long enough to tell Dansby he had to go fetch his playbook. And with that, Crowder's six-year career as a Dolphin was over.

"I was definitely shocked," Dansby said Saturday. "It was a shock to everybody. I hate to see him leave like that.

"We were a top-six defense last year and he was a centerpiece to everybody. Everything meshed around him."

Even Sparano conceded the move was difficult.

"It's one of the hardest things I've ever had to do," Sparano said. "It's still hard for me. But it's football. It happens."

The Dolphins' third-round pick out of Florida in 2005, Crowder, 27, was hugely popular with teammates, but the numbers didn't add up.

He averaged 57 tackles a year and totaled just 2.5 sacks and one interception in his six seasons with the Dolphins. Last year alone, Dansby, who played alongside him, had 96 tackles and three sacks. And Crowder was due to make $5 million this season, the last of a three-year deal he signed in 2009.

To replace him, Miami signed free agent Kevin Burnett, whom Sparano and Ireland knew from Dallas, to a four-year, $20 million deal. Burnett had 80 tackles, six sacks and two interceptions last season.

"Good player. He's going to fit right in," said Tim Dobbins, who played alongside Burnett at inside linebacker in San Diego two years ago. "He's fast, and he's always positive. He's going to bring good energy to the facility."

The 6-foot-3, 240-pound Burnett, 28, was a second-round pick of the Cowboys (and Ireland, then their scouting director) in 2005 and spent four years as a backup before moving on to San Diego, where he became a starter last year.

"This is a guy who can play all three downs, runs really well, cover some of the bigger tight ends and bigger backs in our league," Sparano said. "I think a lot of him. He's a good kid."

Dobbins said he and Burnett became friends during the 2009 season."