The 39-year-old quarterback said he feels like a "young 39."
"I think there's young 39s and old 39s. I'm in that young group, for sure," Manning said with a smile, according to DenverBroncos.com.
Neck problems forced Manning to miss the 2011 season and have given him trouble since he arrived in Denver the following year, and a torn right quad bothered Manning toward the end of the 2014 season.
Manning, who owns the NFL's career passing touchdowns record with 530, is 2,148 yards away from passing Brett Favre's career passing yards record.
Manning threw for 4,727 yards and 39 touchdowns last season for the Broncos, who lost to the Colts in the divisional round of last season's playoffs.
- Erick Fernandez