"Gonna catch some football with my little guy today," the proud new dad father captioned an Instagram photo of himself with the young gridiron fan.
Duhamel and his wife haven't been shy about sharing photos of Axl on social media. The 40-year-old "Safe Haven" actor previously posted an Instagram of his son emblazoned with the words "Go Bison!" a reference to the North Dakota native's favorite college football team.
"First of all, we're obsessed with him," Duhamel told E! News last month. "We can't stop staring at him. He's our little man, we made him together. I think there's something you can't really describe until you go through it. I think any parents out there would understand that…It's just an incredible time for both of us."