Competition motivates him, too. He and Beason, practicing on the backup kickoff team, went all out to see who could get to the goal line first. When Beason tore his Achilles, Davis carried his jersey onto the field the next week -- the very game in which Davis suffered his third ACL tear. Vermillion, the trainer, put them together as rehab partners. They worked out together, 9 a.m. until they gave out, six or seven days a week.
Davis spent weeks just bending and stretching his leg, reclaiming his range of motion one agonizing millimeter at a time. Then he moved to a stationary bike. "I can remember they jacked the seat up so he'd just have to make one little circle," Beason says. "He got up there and tried to pedal and his legs are shaking, he's screaming, that one time from that one circle."
Every ACL rehab equals months of agony. Davis remembers standing up after surgery and the blood flowing into the torn-up spots, the pain so deep it brought tears. Cybex machine, stationary bike, leg extensions, breaking up scar tissue, testing the joint, climbing stairs, learning how to run again. Imagine going through all that. Imagine doing it three times.
Beason made it back, too, but then hurt his knee and shoulder. While he was gone, 2012 first-round pick Luke Kuechly stepped in and became a star. This year, the Panthers traded Beason to the Giants, where he has been a leader on their defense. He and Davis still talk on the phone, reminding each other what they went through.
"Thomas is mentally strong," Beason says. "But I think having the same injury over and over again has to do something to your psyche. To do this for a living, you have to trust your body."
It's one thing when the critics doubt you. It's another when your own body does. And the doubt went into places no one else suspected.
The first time, it stunned him.
It was the eighth game of 2009, Davis' fifth season. The Panthers were playing the Saints at the Superdome. Davis ended up in coverage on Saints receiver Devery Henderson. He planted his leg to bump Henderson off his route. He heard the pop and felt the shock of pain. He was naturally knock-kneed -- which put more stress on the joints -- but he had never been seriously hurt before.
His first thought was Kelly. She was pregnant with their second child together (they have two others from previous relationships). He wanted to do the rehab as fast as he could so he could help out after she had the baby.
But the truth was, he felt lucky to have been playing at all.
This is a story he hasn't told.
In the 2009 preseason, he was doing charity work to make sure young athletes got screened for hidden heart conditions. Davis took a group of kids to a Charlotte hospital that had set up free ultrasounds and EKGs. To show it wasn't scary, he got the first screening himself.
Afterward, the doctors pulled him aside and said they needed to talk.
The coronary arteries ship blood away from the heart. In a normal heart, one originates on the left side of the heart, the other on the right. The screening showed that both of Davis' coronary arteries were on the same side. It's not an especially rare condition; maybe 1 in 200 people has it. It often doesn't cause any symptoms. But when doctors find it, they normally recommend correcting it. That means open-heart surgery. And for Davis, that might have meant the end of his career.