Peyton Manning appears to be far less than 100 percent heading into Sunday's matchup with the division-rival Kansas City Chiefs.

The Denver Broncos' star quarterback, who was listed as probable Friday with a foot ailment, had a rib-cage issue added to his injury report status Saturday morning.

Manning remains probable for the game, and there's been no indication that his playing status is at all in jeopardy, but staying healthy is imperative to ensuring that he remains at the top of his game down the stretch.

The multiple injuries will be worth monitoring Sunday as Manning and the Broncos look to bounce back from their first defeat of the season last week.

Emmanuel Sanders is still considered questionable after an ankle injury kept him out of practice throughout the week.

Head coach Gary Kubiak said Friday that the wide receiver was "really sore," when he attempted to participate in some drills, indicating that his availability would likely come down to a game-time decision.