Mike Nolan is known for quick turnarounds, so it shouldn't be a surprise the defensive wizard spent so little time on the open market after he and Denver Broncos coach Josh McDaniels opted to part ways this week.

Less than 24 hours after Nolan resigned following just one season with the Broncos, the Dolphins scooped him up Tuesday to run a defense that sagged toward the bottom of the NFL rankings in 2009 under Paul Pasqualoni, who was fired.

Nolan, 50, quickly traveled to South Florida to meet with Dolphins coach Tony Sparano, with whom he's never worked in an NFL career that dates back more than two decades. Bill Parcells, the Dolphins' football operations czar, hired Nolan to run the Jets defense in 2000, so no introduction was needed there.

This will be Nolan's sixth stop as a coordinator, following previous stays with the Giants (1993-96), Redskins (1997-99), Jets, Ravens (2002-04) and Broncos. Nolan also spent 3½ seasons as head coach of the 49ers from 2005-08, going just 18-37.

Dick Nolan, his late father, was an NFL head coach with the 49ers and Saints and ran Hall of Fame coach Tom Landry's Dallas defenses in the '60s.

After dumping Pasqualoni on Jan. 11, the Dolphins pursued longtime Parcells ally Al Groh and Steelers assistant Keith Butler. In each case they were rebuffed, but this week's developments have to leave those at Dolphins headquarters feeling as if they hit the lottery.

Under Nolan, the Broncos improved from 29th in total defense to seventh. He switched them from a 4-3 defense to his aggressive 3-4 scheme, and the result was a pass defense that improved from 26th to third.

Three key free agent signings in the secondary – Pro Bowl safety Brian Dawkins and ex-Dolphins Renaldo Hill and Andre' Goodman – were vital to the turnaround as well.

Undersized defensive end Elvis Dumervil was shifted to outside linebacker and led the NFL with 17 sacks despite standing just 5 feet 11. The Broncos defense had 39 sacks in 2009; the Dolphins had 44 while allowing a league-worst 8.2 yards per pass attempt and finishing 24th in pass defense.

Defending the run was another matter for the Broncos, who improved only slightly (from 27th to 26th) under Nolan. The Dolphins were 18th.

Nolan probably wouldn't have left Denver if the Broncos hadn't followed a 6-0 start by losing eight of their last 10. They allowed 27 or more points in seven of their final 10 games, including an average of 30.5 in dropping four straight to end the year and miss the playoffs, which reportedly led to tension on the coaching staff.

Late-season disappointment has dogged Nolan in the past. Just three of the 16 teams he has served as a coordinator or head coach have made the playoffs: '93 Giants, '99 Redskins and '03 Ravens.

Earlier Tuesday, the Dolphins announced the hiring of Bill Sheridan as their inside linebackers coach. Sheridan, fired by the Giants after five seasons – the last one spent running their disappointing defense -- replaces George Edwards, now the defensive coordinator at Florida.

The Dolphins are still looking for an outside linebackers coach to replace Jim Reid, who left for Virginia.

Mike Berardino can be reached at mberardino@SunSentinel.com and read regularly on the Dolphins blog at SunSentinel.com/dolphins.