SANTA CLARA, Calif. -- It is common knowledge that before being promoted to head coach last January, Jim Tomsula had been the San Francisco 49ers' defensive line coach since 2007.

But from 2011 through last season Tomsula answered to defensive coordinator Vic Fangio, who was passed over in favor of Tomsula for the head-coaching gig despite linebacker NaVorro Bowman saying he wanted Fangio retained, either as head coach or defensive coordinator.

Surely there will be some awkwardness this weekend at Soldier Field when Tomsula’s Niners take on the Bears and Fangio, now Chicago's defensive coordinator, no?

“Vic’s a really good football coach,” Tomsula said Thursday, “and obviously we all had a great run during that time ... that was good. So I don’t have anything but fond feelings and that was really good stuff.

“It was a very good thing.”

Under Fangio, the Niners had top-five defenses all four seasons, and the Niners went to three straight NFC championship games including an appearance in Super Bowl XLVIII.

This year, after an offseason of defections via retirement and free agency, the Niners' defense is ranked 29th in the NFL.

Fangio, meanwhile, has the Bears ranked 14th in total defense after they finished 30th last season. He was asked Wednesday about being passed over for the Niners gig.

“That’s their decision and their choice,” Fangio said. “I have nothing to do with that.

“I’ve just accepted it’s their decision, their team. They do what they want with it.”

After passing over Fangio and Adam Gase, who is now the Bears' offensive coordinator, the Niners' braintrust went with Tomsula, who said he did glean some things from Fangio in their four years together.

“Vic does a nice job,” Tomsula said. “His breakdowns and the way he approaches things, everybody does it different, so even when you work with different people you see different things. So yeah, I mean, every day you’re learning from guys and Vic, Vic is a really good football coach.”