By moving swiftly to replace Vic Fangio with arguably the best and most experienced coach with a background in a 3-4 scheme, the Bears took care of the most important step at the start of their offseason.

Chuck Pagano and Fangio worked together with the Ravens in 2008-09, so the new defensive coordinator is quite familiar with what the Bears have been doing on defense for the last four seasons.

Now it’s a matter of sorting out who will work alongside Pagano under coach Matt Nagy. Most questions right now surround secondary coach Ed Donatell, who is coming out of contract and will be able to choose what he wants to do without being blocked.

It’s believed the Bears and Broncos have interest in Donatell, who is credited with helping improve the entire core of players the Bears used at cornerback and safety the last couple of seasons. Donatell interviewed for the Bears’ coordinator job on Thursday, a day before Pagano was hired. The Broncos potentially could offer Donatell that title in Denver, though Fangio is expected to call the defense there. That title likely would mean a pay raise for Donatell as well. Or he could return to the Bears and a team coming off a 12-4 season and an NFC North title with a defense that will enter 2019 as one of the league’s best.

Outside linebackers coach Brandon Staley is well-regarded at Halas Hall, but he is not expected to return, according to a source familiar with the situation. Staley reportedly will interview with Fangio and the Broncos on Monday. That could be a case of the Bears allowing Fangio to bring a trusted coach with him while giving Pagano an opening to fill with someone he has worked with previously.

Another source said Roy Anderson, who joined the Bears in 2017 as assistant defensive backs coach, will not return. The team has not made any announcements since releasing news of Pagano’s hiring. Anderson worked with Pagano on the Ravens staff and then with the Colts from 2012 through 2015.

The coaching carousel is fluid, especially when it comes to position coaches and assistants. Rumors fly, and one making the rounds Sunday morning was that the Bears could consider Rob Ryan, the son of Buddy Ryan, architect of the 1985 Bears defense. Rob Ryan has been a defensive coordinator for the Saints, Cowboys, Browns and Raiders and last worked for the Bills as head coach/defense in 2016. Ryan was the defensive coordinator in Oakland when Pagano worked under him as a secondary coach.

Another name some wondered about is John Pagano, Chuck’s younger brother, who is a senior defensive assistant working with outside linebackers for the Texans. Whether or not he’s available remains to be seen. John Pagano also has been a coordinator previously with the Raiders and Chargers.

It likely won’t take the Bears long to work through staff adjustments. It’s not like last year when Nagy, a first-time coach, was building a staff from scratch. Some expect a decision on Donatell to come soon. Pagano is well-respected, and the Bears are an attractive destination.

bmbiggs@chicagotribune.com

Twitter @BradBiggs

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