The eighth pick of the 2017 draft was hiking with family and friends in Castle Rock, Colorado, on Saturday when they witnessed Dan Smoker Sr., 72, fall about 20 feet onto a rock while hiking with his grandson, Eli Smoker.
McCaffrey immediately called 911 and then rushed with others in his group to help Smoker, who at the hospital was determined to have suffered a broken femur, pelvis and neck, fractured ribs and had bleeding on the brain.
"I credit them with saving my dad's life," Smoker's son, Dan Smoker, told Panthers.com on Tuesday.
McCaffrey was hiking with his brothers, Dylan and Max, and friends Michael Mann and Brooke Pettet when they walked up on the fall as it occurred.
"It felt like he was in the air for 10 seconds," McCaffrey told the team website. "I had never seen anything quite like that in my life as far as the trauma and the sound. We were in shock."
But not so much that they didn't respond quickly. A fellow onlooker identified as Chris held Smoker's head to keep him still. Mann performed chest compressions when Smoker stopped breathing.
"Everybody stepped up," McCaffrey said. "I called 911, and it felt like an eternity. It felt like we were up there waiting for four hours. But I looked back at my call log and it took 11 minutes before the paramedics came. Amazing what those guys did."
That McCaffrey & Co. were at Castle Rock was random. They were on the way to lunch when a member of the group suggested they go hike.
The next day McCaffrey, along with his mom, Lisa, and brothers went to the hospital to check on Smoker, who remains in critical but stable condition.
When they introduced themselves, Eli and his dad hadn't figured out that McCaffrey was the Panthers star and the son of former Denver Broncos receiver Ed McCaffrey.
"I can't say I'd recognize Christian without his football gear on," Dan Smoker told the website. "Around here, Valor Christian is a popular high school, and I knew that Ed McCaffrey had just taken over as head coach there. We were talking and they had mentioned that they went to Valor, and we were looking there because our son loves football as well.
"At that point, Lisa chimed in and said, 'Well, we may have a contact.'"
McCaffrey, who led the Panthers with 80 catches this past season, has kept in touch with the Smokers since via text.
"Eli was such a trouper, man," McCaffrey said. "I was traumatized, and I had no relation."
Now they're bonded by a moment none will forget.
"Truly a blessing that we turned the corner at that exact moment and we could be there for him," McCaffrey said. "I don't know what would have happened ... We were lucky to be at the right place at the right time."