One of the big prizes on this year's market, Dansby visited the Dolphins in the opening hours of NFL free agency. All it took was the NFL's richest deal for a linebacker to keep Dansby from visiting any other teams.
By Friday night, Dansby and the Dolphins had agreed to a five-year contract worth $43 million, with $22 million guaranteed, a league source told NFL Network's Jason La Canfora. Dansby is scheduled to make an average of $9 million over the first three years of the deal.
The Dolphins said Saturday that the deal had been signed.
Dansby, who has played inside and outside linebacker, became an unrestricted free agent after six seasons with the Arizona Cardinals, but La Canfora cited a league source in reporting Friday that the team was making a strong push to keep the linebacker. Apparently, Arizona's efforts weren't enough.
To make room for Dansby, the Dolphins terminated the contracts of disgruntled outside linebacker Joey Porter, inside linebacker Akin Ayodele and free safety Gibril Wilson on Friday.
Porter, a four-time Pro Bowler who was chosen to the NFL's All-Decade team in January, was released last month, but he returned to the roster because of a salary-cap technicality. He had campaigned to be released while complaining about his reduced role last season and his relationship with coach Tony Sparano.
Wilson struggled in his only season with the Dolphins. He received $8 million guaranteed when he signed last year.
Ayodele was a two-year starter at inside linebacker, but Dansby offers more big-play ability. The former Cardinals star has 25.5 sacks, 10 interceptions, 12 forced fumbles and nine fumble recoveries in his NFL career.
A second-round draft pick by Arizona in 2004, Dansby has been a starter since his rookie season. He made one of the most memorable plays in this year's playoffs, returning Aaron Rodgers' fumble 17 yards for a touchdown to give the Cardinals a 51-45 overtime victory over the Green Bay Packers.
As Friday's moves made clear, the Bill Parcells regime is eager to improve a Miami defense that last season gave up a franchise-record 140 fourth-quarter points, most in the NFL. In the final three games, desperate to stay in the playoff race, the Dolphins fell behind 24-6, 27-0 and 27-10.
The Associated Press contributed to this report.