The Broncos lost to the Colts 24-13 in the divisional round. Manning completed 26-of-46 passes for 211 yards and one touchdown and was sacked twice.
The 38-year-old originally tore his quad during a Dec. 14 win over the San Diego Chargers, reports Schefter, who said an MRI later confirmed the tear. The injury is specifically a torn rectus femoris, according to Schefter, and the "bruising was so severe it spread to back of his leg."
However, CBS Denver's Vic Lombardi and The Denver Post's Troy E. Renck report the injury would be more accurately described as a strain rather than a "complete tear." A quadriceps strain is considered a partial tear of "the small fibers of the muscles" that makes up the quad group.
Including Sunday's loss, Manning and Denver played three games after the injury and went 1-2. In the game immediately after sustaining the injury, the veteran threw four interceptions in a 37-28 loss to the Cincinnati Bengals.
According to the Post, Manning has been receiving treatment on the quad for several weeks and missed consecutive practices for the first time since joining Denver during the team's playoff bye week.
Manning was noncommital after Sunday's loss about coming back for another season. He will turn 39 in March, and after multiple neck surgeries over the past several seasons, his health has been a persistent topic.
"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 finished the regular season having completed 66.2 percent of his passes for 4,727 yards, 39 touchdowns and 15 interceptions, the latter of which was his highest total in a Broncos uniform.
Denver won the AFC West after going 12-4 in the regular season.
- Molly Geary and Mike Fiammetta