The Colts won, 24-13, in Denver. Manning went 26 of 46 for 211 yards and a touchdown, which was the game's first score five minutes in.
Manning will turn 39 in March, and after multiple neck surgeries over the past several seasons, his health has been a persistent topic surrounding the future Hall of Famer and the Broncos.
"That's kind of what I've said all along. But I can't answer every what-if circumstance," Manning said Sunday, according to The Denver Post. "What if you're not as healthy? What if certain coaches leave? I can't answer every what-if situation. I think I'll have to take some time to see how I feel, see how I feel physically.
"Yeah my mindset right now is just disappointment after today's game. Dave Logan [of 850 KOA radio] asked me about it after the game, and like I said, I didn't have a great answer for him. So I'm disappointed. I kind of need to process this game and we'll meet tomorrow. I need to process this game."
Manning also said he sustained a thigh injury in Week 15 against the San Diego Chargers that "kind of hung around" this season.
After opening Sunday's game vs. the Colts with Manning's 1-yard touchdown pass to Demaryius Thomas, the Broncos were outscored 14-3 in the second quarter and then held scoreless in the third. That allowed the Colts to bring a 21-10 lead into the fourth quarter, when the Broncos managed only a 41-yard field goal by Connor Barth.
This season, Manning was fourth in passing yards (4,727), second in touchdowns (39), sixth in completion percentage (66.2 percent) and fourth in passer rating (101.5).
- Mike Fiammetta