The Denver Broncos and defensive coordinator Mike Nolan have agreed to part ways, and a source told ESPN.com's John Clayton that Nolan is close to an agreement to take on the same role with the Miami Dolphins.
Before the split, Miami sent in a request for permission to interview Nolan, sources close to the situation told ESPN NFL Insider Adam Schefter. The parting was friendly and gave Nolan a chance to move on and talk to the Dolphins, the source told Clayton.
The Dolphins fired defensive coordinator Paul Pasqualoni and have struggled to find a quick replacement. The Dolphins' interest in Nolan apparently opened the door for the chance for Nolan to get to Miami.
Nolan becomes the third member of coach Josh McDaniels' inaugural staff to depart following a disappointing 8-8 finish. Offensive line coach Rick Dennison left for Houston's staff and longtime running backs coach Bobby Turner was reunited with Mike Shanahan in Washington. Both Dennison and Turner were holdovers from the Shanahan era.
"I can't say anything other than Josh and I mutually agreed to part ways," Nolan said on Monday, according to The Denver Post.
Nolan, who engineered the Broncos' switch to a 3-4 defensive alignment, was McDaniels' first hire. McDaniels lined up Nolan to help revamp what had been a deplorable defense.
McDaniels said in a statement released Monday by the team: "I have great respect for Mike and wish him success in the future."
As a potential replacement, the Broncos already are discussing former Patriots defensive coordinator Dean Pees, who worked with McDaniels in New England, sources told Schefter.
The Broncos started the season 6-0 and were the talk of the league. Nolan received much of the credit as he turned around a defense that ranked near the bottom of the league in every major category in 2008.
Nolan's scheme shaved 7.8 points a game off a defense that surrendered 28 points a game the previous season.
Then the team went into a free fall, losing eight of its next 10 games to miss the postseason for a fourth straight year.
Now, the Broncos will be searching for their fifth defensive coordinator in five seasons.
After getting fired as head coach of the San Francisco 49ers in 2008, Nolan tried his hand in broadcasting but found himself wanting to return to coaching.
Then McDaniels came calling, offering him a chance to turn around the Broncos' defense that had slid under Shanahan's watch.
Known as a defensive wizard, Nolan jumped at the challenge.
He holed up in his office last offseason as he installed a new look and shuffled around personnel.
Denver gave him the pieces, bringing in perennial Pro Bowler Brian Dawkins to serve as a leader and add a swagger that had been missing. Dawkins sparked the Broncos.
One of the biggest beneficiaries of Nolan's system was Elvis Dumervil, who was able to use his long arms and low center of gravity off the edge of the line as a hybrid defensive end/linebacker. Dumervil turned in a Pro Bowl season as he finished with an NFL-leading and team-record 17 sacks.
Once again, though, Dumervil and his defensive teammates will be under a new defensive boss.
Dumervil will be a restricted free agent if there's no collective bargaining agreement. Come next season, he will be working for his eighth defensive coordinator in eight seasons, including three at the University of Louisville.
Information from ESPN.com senior writer John Clayton and The Associated Press was used in this report.