To retain Ryan, the Ravens likely have to give him a significant raise. Ryan is in the final year of a two-year contract that is worth between $1 million and $1.2 million a season.
The offensive coordinator could be Philadelphia Eagles quarterbacks coach Pat Shurmur or recently fired Miami Dolphins head coach Cam Cameron, a league source said.
Harbaugh has a chance to keep Ryan because they had a solid relationship during their one season together at the University of Cincinnati. In 1996, Harbaugh was the assistant head coach at Cincinnati, and Ryan was the defensive coordinator.
But it's a delicate situation, because the Ravens interviewed Ryan for the head coaching job but did not consider him a finalist.
A league source said he's been offered defensive coordinator jobs from three teams, with Miami presumably one of them.
Though Ryan was recently let go, it's unclear whether he can take a coordinator position with another team because he is technically under contract.
Besides an increased salary, the Ravens also offer a comfort zone for Ryan. He is extremely loyal to his players, who campaigned heavily for him to become head coach.
If the Ravens can't keep Ryan, they likely would consider Ron Rivera, a former defensive coordinator who is the San Diego Chargers linebackers coach.
It is believed that Harbaugh will talk to Cameron and Shurmur for the offensive coordinator job.
Shurmur has been linked to Harbaugh because they have coached with the Eagles the past nine seasons. But Shurmur has a year left on his contract, and the Eagles could block the move.
Cameron is a possibility because Harbaugh was on his staff at Indiana.