NASHVILLE, Tenn. -- Getting permission to interview an assistant who is under contract is difficult business in the NFL.
Maybe San Diego wants to run away from tight ends coach Jason Michael. Maybe Pittsburgh wants to run away from linebackers coach Keith Butler.
I doubt it.
While those teams might want to keep those coaches, perhaps they are also doing a nice thing for quality employees and giving them a chance to look into a promotion, even if it comes elsewhere.
Perhaps part of it is that the Chargers and Steelers hold new Tennessee Titans coach Ken Whisenhunt in high regard, and that makes them more inclined to say yes. Perhaps in Butler's case, the Steelers feel badly about denying permission in the past and grant it.
For whatever reason, Ruston Webster and Whisenhunt got permission from San Diego and Pittsburgh, per Jim Wyatt of The Tennessean.
So for offensive coordinator, it looks like Michael or John McNulty, the former Tampa Bay quarterbacks coach.
And for defensive coordinator, it looks like Butler or Ray Horton, who has been granted broad permission by the Cleveland Browns to explore other opportunities.
UPDATE, 3:40 ET: Gerry Dulac of the Pittsburgh Post-Gazette says Butler will remain with the Steelers.