The biggest concern surrounding the San Francisco 49ers' reunion with Robert Saleh is the possibility of him becoming the team's third consecutive one-and-done defensive coordinator.

Saleh, who was fired in October as the New York Jets head coach five games into his fourth season, generated interest on the head-coaching front and was seen as one of the frontrunners for the Jacksonville Jaguars job. He also interviewed with the Las Vegas Raiders and Dallas Cowboys.

Robert Saleh is expected to return to the 49ers as their defensive coordinator if he doesn't become a head coach according to The Athletic and NBC Sports Bay Area.

The 49ers and Jets both enjoyed top-five defenses under Saleh. There’s little reason to expect Saleh to stray away from what’s made his defenses elite. There also may not be m