Baltimore Ravens defensive coordinator Dean Pees, one of the league's top defensive minds, is expected to retire after this season, league sources told ESPN's Adam Schefter.

Pees, 68, has coached in Baltimore since 2010, and before that he was the New England Patriots' defensive coordinator from 2006 to 2009. In that time, Pees developed a reputation for being able to adjust his defenses to the game, creating exotic looks for opposing offenses and being able to work with players.

Pees has not told Ravens players of his intentions yet, but his plan is to leave the game after this season, sources said.

Former Ravens linebacker Ray Lewis said earlier this season: "Look, let's just give credit to Dean Pees and what he's been doing with defenses for ages. When you see this defense play, they are aggressive, they are physical, and they are telling people, 'We can absolutely beat you up.' That's always been our simple motto: You want to come in and act cute? We're coming in to punch you in the mouth. And that's what the Ravens are doing."

As for a successor, the Ravens typically promote from within. Under coach John Harbaugh, all four defensive coordinators -- Rex Ryan, Greg Mattison, Chuck Pagano and Pees -- were preciously position coaches on staff. Pagano, the defensive coordinator in 2011, is expected to be available if the Indianapolis Colts part ways with him.

Linebackers coach Don "Wink" Martindale would be considered the top in-house candidate. He was previously the defensive coordinator for the Denver Broncos.

The Ravens -- who lead the NFL with three shutouts this season -- head into Sunday's regular-season finale against the Cincinnati Bengals at 9-6 and needing a win to guarantee a playoff spot. They also lead the NFL with 22 interceptions, 33 forced turnovers and a plus-17 turnover margin. They also are fourth in points allowed per game and ninth in yards allowed per game.

ESPN's Jamison Hensley contributed to this report.