If the Buffalo Bills do indeed step up in a big way in 2020, defensive coordinator, assistant head coach and former Vikings head coach Leslie Frazier will step back into the head coaching ranks in 2021.

The first part of this prediction is expected. Or at least it should be, despite oddsmakers sticking with New England to win the AFC East without Tom Brady and six players who opted out of the season because of COVID-19.

The Bills, who last year posted 10 victories for the first time this millennium, are better offensively with Stefon Diggs. They are better defensively with more pass rushers in Mario Addison and rookie A.J. Epenesa. And, oh yeah, they don't have to play Brady, who went 32-3 against a Bills team that hasn't won the AFC East since 1995.

The second part of this prediction is aided by three factors:

1. Frazier may work for a defensive-minded coach in Sean McDermott, but Frazier calls the defense on game day and has a significant role in shaping the game plan.

McDermott rewarded Frazier this offseason by adding assistant head coach to his title.

"His fingerprints are all over our operation, and I'm extremely grateful for all the years we have worked together," said McDermott, who was hired in 2017. "Leslie's impact on our team is felt every day through his guidance, wisdom and his genuine care for people. He is a great example to everyone within our organization."

2. Frazier's defense ranked No. 2 in points allowed last year. At 16.2 points per game, it was the fewest points allowed by a Bills team since 1999.

3. There will, of course, be multiple opportunities as NFL teams keep dumping coaches. Doug Marrone in Jacksonville, Dan Quinn in Atlanta and Matt Patricia in Detroit already are sitting on three of the hotter seats in the league.

And with those opportunities, Frazier, who is Black, should benefit from changes to the Rooney Rule. Among those changes is teams with head coaching vacancies must now interview two minority candidates outside their organization.

Frazier has had multiple interviews since being fired by the Vikings after going 21-33-1, including 0-1 in the playoffs, from 2010 to '13. But he got no interviews as five teams sought head coaches after last season.

The league has only four head coaches who are men of color. Speaking on the podcast "One Bills Live" in Buffalo in June, Frazier said the changes to the Rooney Rule were warranted.

"Historically, before the Rooney Rule, it was just so difficult for a minority to get an interview for a coordinator job or a head coaching job, for whatever reason," Frazier said. "Then after the Rooney Rule, you saw the increase because of the mandate.

"But over time, you've seen it's gotten watered down because people have gone through interviews but never really had a legitimate shot at the position. The tweaks they're making now, we'll see what happens. But the history of the NFL says the Rooney Rule was necessary."

Frazier turns 62 in April, but that shouldn't hurt him. First, he's vibrant. Second, teams don't dismiss guys based on birthdays. Last year, Denver gave Vic Fangio his first head coaching job at 60.

Frazier's end with the Vikings wasn't pretty. The 2013 team went 5-10-1 and finished last in scoring defense (30.0).

Yes, Frazier's scheme was considered tired and predictable by then. But the key members of his front seven had grown old and his alarmingly overmatched secondary was hamstrung by injuries, inexperience and some overrated players — such as Chris Cook — who never panned out.

Frazier also was extremely frustrated by the loss of cornerback Antoine Winfield in a cap-cutting move that March. And his quarterbacks were — look away if you must — Christian Ponder, Matt Cassel and Josh Freeman, who got $3 million that year to play one atrocious game on an infamous Monday night in the Meadowlands.

Since that year, Frazier has done a nice job rehabbing his career. One more giant step by the Bills this season, and he could make it back to the top.

Mark Craig is an NFL and Vikings Insider. Twitter: @markcraigNFL. E-mail: mcraig@startribune.com