49ers have interviewed at least 4 defensive coordinator candidates [reports]

The 49ers' defensive coordinator search lingers on, and there are at least four names in the mix.

While Kyle Shanahan has had a great deal of success with internal promotions, and seeks to keep the 49ers' foundation as a 4-3 base defense intact, there is not a cut-and-dry, in-house choice to replace Steve Wilks.

John Lynch confirmed Tuesday that the team had interviewed defensive passing game specialist/nickels coach Nick Sorenson, and that safeties coach Daniel Bullocks was next. Bullocks, per Adam Schefter, completed his interview Thursday.

Outside of the organization, Lynch confirmed that former Chargers head coach Brandon Staley was interviewed.

Also on Wednesday, Mike Garafolo reported that the 49ers would interview Chiefs defensive backs coach Dave Merritt, who has spent 10 years under Steve Spagnuolo.

The 49ers must interview at least one more outside minority candidate after their interview with Merritt, who is Black. That means at least five candidates will get interviews for the defensive coordinator job before Shanahan comes to his conclusion.