The defensive coordinator who keyed Michigan's dramatic turnaround in 2021 is on the cusp of heading back to the NFL.

The Baltimore Ravens have targeted Michigan defensive coordinator Mike Macdonald, a former Ravens assistant, to be John Harbaugh's next defensive coordinator, sources told ESPN.

A deal is expected to be finalized in the coming days, according to sources. Macdonald has been replaced on the road recruiting by a graduate assistant coach, Dylan Roney, in preparation for his departure.

The Detroit Free Press first reported that the Ravens were targeting Macdonald.

This comes after Macdonald stabilized a defense that keyed a one-year turnaround for Jim Harbaugh at Michigan, as the Wolverines went from 2-4 in 2020 to the College Football Playoff and a 12-2 record this past season.

Michigan's scoring defense under Macdonald improved from No. 95 in 2020 with 34.5 points per game to No. 8 with 17.4 PPG. Michigan went on to beat Ohio State for the first time since 2011 and win the Big Ten for the first time since 2004.

Macdonald's hire at Michigan proved to be one of the most impactful in all of college football last season. His schemes helped eliminate Michigan's propensity under former defensive coordinator Don Brown to give up big plays. Under Macdonald, the Wolverines yielded 100 fewer yards per game in 2021, an average of 330.8 after giving up 434.3 the prior season.

Macdonald also helped launch the Heisman candidacy of defensive end Aidan Hutchinson, who was a finalist for the award after finishing with 14 sacks and two forced fumbles.

Macdonald, 34, would become the youngest defensive coordinator in the Ravens' 26-year history. Before leaving for Michigan last year, Macdonald spent seven years in Baltimore (2014-20), having joined the Ravens in 2014 as an intern. He was Baltimore's inside linebackers coach for three seasons (2018-20) and was considered the heir apparent for defensive coordinator there before leaving for Michigan.

The Ravens fired Don "Wink" Martindale on Friday after the sides were unable to agree on a contract extension through 2023, a source said. Under Martindale, the Baltimore defense ranked in the top 10 in three of four seasons.

Macdonald would take over a Ravens defense that finished No. 25 in the NFL last season. That was Baltimore's worst defensive ranking since it was 25th in 1997.

In 2018, Macdonald interviewed for the Ravens defensive coordinator position that eventually went to Martindale. Now, four years later, it appears Macdonald will get his chance to step into that role.