The Baltimore Ravens are expected to hire Mike Macdonald as defensive coordinator.

Macdonald previously worked for the Ravens before becoming defensive coordinator at Michigan. Macdonald's hire at Michigan proved to be one of the most impactful in all of college football last season. 

The Ravens fired Don "Wink" Martindale on Friday after the sides were unable to agree on a contract extension through 2023. In 2018, Macdonald interviewed for the Ravens defensive coordinator position that eventually went to Martindale.

The Baltimore Ravens are nearing an extension with John Harbaugh, according to a source.

Harbaugh, 59, is entering the final year of a four-year deal that he signed in January 2019.

He has led the Ravens to a playoff berth in nine of his 14 seasons and guided the franchise to its second Super Bowl title in 2012.

The Baltimore Ravens have fired Don Martindale as defensive coordinator with one year remaining on his contract.

John Harbaugh issued a statement Friday saying he and Martindale "agreed to move forward in separate directions."

"We have had a great run on defense, and I am very proud of what has been accomplished and the work he has done," Harbaugh said in his statement. "Don has been a major contributor to the success of our defense since 2012, and especially since he became defensive coordinator four years ago. He has done a great job. Now it is time to pursue other opportunities.

"Sometimes the moment comes, and it's the right time. I am personally grateful for our friendship and for everything he has done in Baltimore."

The decision came 12 days after the Ravens' season-ending, 16-13 overtime loss to the Pittsburgh Steelers and came after Martindale had participated in personnel meetings last week. 

Baltimore ranked No. 25 on defense last season, the first time the Ravens had finished out of the top 10 in Martindale's four seasons as defensive coordinator.