While that appears not to be the case, he will undergo a heart procedure and be away from the Broncos for the next month. From NFL insider Jay Glazer:
Fox was slated to have this procedure in the offseason but held off. Ironically, he flew to North Carolina during this weeks bye to meet w surgeon about a February procedure.
Although he'll be away from team he'll still be involved
Fox told Glazer that “it's something I've known I needed to take care of for a while. It's ironic this happened when I came to meet with the surgeon. I was hoping to wait but it's better to be smart about this.”
The Broncos have a former NFL head coach in defensive coordinator Jack Del Rio to helm the team in his absence. As for the Broncos' unstoppable offense, I'm sure Peyton will be fine for a bit without his coach.