The Broncos fired coach Mike Shanahan after the 2008 season. He hadn't returned to the team's facilty, until today.
Shanahan was back on Saturday, at the invitation of new coach Vic Fangio.
"I was glad to have Mike here," Fangio told reporters. "I invited him out, wanted him to come. I invited him for the spring work and schedules never matched up, but I was glad he was here. I think it's good he's here. Mike's got a big part in the rich history of this franchise. He's welcome to come here anytime he wants."
Shanahan led the Broncos to their first two Super Bowl wins; he's one of only six coaches with consecutive Super Bowl victories.
Fangio explained that he and Shanahan have gotten to know each other over the past five-to-eight years. They have a much longer history as competitors.
Shanahan coached in Washington from 2010 through 2013. He has periodically expressed a desire to have a third head-coaching a fourth head-coaching stint (he also coached the Raiders in the late 1980s), but he has never generated much interest.