Buffalo's Damar Hamlin suits up Sunday for his first regular-season NFL game since a heart-stopping hit during a contest in January while Miami's Tua Tagovailoa is back after multiple concussions.
The health of both players will be greatly scrutinized during the 2023 campaign, especially after two NFL pre-season games were stopped early due to injuries suffered by Miami's Daewood Davis and New England's Isaiah Bolden.
"You could see in the collective faces of both teams, their mind wasn't on playing football," said Dolphins coach Mike McDaniel after Davis was hurt late in a game at Jacksonville. "It was inappropriate to play football."
NFL concussion rules were tightened in the wake of Miami quarterback Tagovailoa being stretchered off the field last September. The 25-year-old admitted he pondered retirement but is back after a recovery regimen that included jiu-jitsu to better learn how to handle falls.
Hamlin's heart stopped beating after the Bills safety was hit making a tackle in a regular-season game last January at Cincinnati. Medical workers restored his heartbeat on the field and he recovered well enough to return to the team this season.
"How awesome is that?" Bills coach Sean McDermott said. "What a story of courage and faith. Just an unbelievable amount of will power he has displayed to the world.
"It's surreal in so many ways and now we're able to have him with us to start the season. We can't wait to see him play this year and watch how he's going to help our football team win games."
Tagovailoa staggered and collapsed after a tackle last September against Buffalo, but he was diagnosed with a back injury and returned to spark a Dolphins victory.
Four days later, however, he was slammed to the ground when sacked in the second quarter at Cincinnati and his helmet struck the ground.
Tagovailoa was taken off on a stretcher and missed two games while in concussion protocol. The NFL later changed concussion check rules that would have forced him to be examined after wobbly walking.
He suffered a second concussion against Green Bay in December and missed the final three games of the season.
During the off-season, Tagovailoa improved his diet and exercise and took jiu-jitsu training to cope with hitting the turf.
"It went a lot more into the technique of how to disperse your energy when you fall, kind of like the posture you want to be in, and if you're not presented that posture, what are other things that you can do to help you disperse the energy when you fall," he told the Miami Herald.
"I did the best that I could to get myself ready and prepped for this season as far as injuries go."
As McDaniel put it: "We're getting the absolute best version of Tua."
- New helmets for QBs -
The NFL revealed last February there were 149 diagnosed concussions in the 2022 season, an 18% increase from 2021.
Pittsburgh Steelers quarterback Kenny Pickett, who suffered two concussions as a rookie last year, is wearing, like Tagovailoa, the new VICIS Matrix QB helmet, graded the safest in lab tests by the NFL and its players union.
Pickett's injuries came after his head struck the turf following tackles.
"The worst hits are from the ground and not actually getting hit by a player," Pickett said. "Now that I have a little better protection from the ground, I feel a little better about it."
It's the first year for helmets specially designed for quarterbacks after position-specific helmets were first used by linemen last season.
"You can't really protect yourself when you go to the ground," Pickett said. "The whiplash to the ground for quarterbacks is more than it is for other positions."
Guardian Caps, protective devices worn on the outside of helmets for training camp workouts in 2021 and 2022, will be mandatory for linemen, linebackers and running backs during padded regular-season practices this year.
With the Caps, there were 25 concussions in training camp practices last year, the fewest in eight years.
NFL data showed the caps absorb about 12% of the force of blows and reduce the impact force by 20% if two players wearing caps are involved.
NFL spokesman Jeff Miller said that over the next three to five years, helmet improvements will incorporate benefits of the Guardian Cap.