Damar Hamlin had the American sporting community rooting for him after the Buffalo Bills safety suffered an on-field cardiac arrest, as team-mate Josh Allen pleaded: "Please pray for our brother."
Hamlin was in a critical condition at the University of Cincinnati Medical Center, having collapsed during Monday's game against the Cincinnati Bengals.
Hamlin made a tackle on Bengals receiver Tee Higgins in the first quarter, and after briefly returning to his feet, he slumped to the ground.
He was administered CPR on the field, before being loaded into a waiting ambulance and rushed away.
Amid harrowing scenes, the game was suspended while the Bengals were leading 7-3 with 5:58 remaining in the first period.
Allen led the call for prayer for Hamlin, with well-wishers from across sport, entertainment and politics also sending thoughts and best wishes.
Former Chargers and Saints quarterback Drew Brees wrote on Twitter: "Damar Hamlin represents every one of us and every team-mate we've ever had.
"I've never met him, but I know him as a member of our brotherhood. My family and I pray for him and his family as he recovers. God be with him."
Michael Vick and Patrick Mahomes also said they were praying for Hamlin, the latter adding: "Please be okay man."
Tennessee Titans quarterback Ryan Tannehill added: "Praying for Damar Hamlin, his family and everyone in Buffalo... no words for a situation like this."
The NFL said: "Our thoughts and prayers are with Damar, his family and the Buffalo Bills."
Arizona Cardinals defensive end J.J. Watt said: "The game is not important. Damar Hamlin’s life is important. Please be ok. Please."
From basketball, the NBA said: "The entire NBA family's thoughts and prayers are with Damar Hamlin, his family and the NFL community."
That was reflected in post-game comments from a number of leading stars after Monday's NBA action, with Lakers superstar LeBron James saying: "My thoughts and super prayers goes up to the skies above for that kid's family, for him, for that brotherhood of the NFL and everybody a part of the NFL family."
James said it was "definitely the right call" to abandon the game for the night.
He said of the incident: "It was a terrible thing to see and I wish nothing but the best for that kid, for the city of Buffalo, for the franchise of the Bills and like I said, for the rest of the NFL as well and also the Bengals that was there and playing in that game."
Klay Thompson, from the Golden State Warriors, added: "As athletes, sometimes the game can overshadow us as individuals or people.
"On behalf of the organisation, we wish him the best. We're keeping him in our prayers and hoping for the best possible outcome. He's a tremendous person and it's bigger than the sport."
Hollywood actor Ben Stiller, a big sports fan, wrote: "Sending good thoughts and prayers to Damar Hamlin and his family."
Former New York City mayor Rudy Giuliani said: "Our prayers are with Damar Hamlin."
Amid the focus on Hamlin's plight, there was a surge in donations to a Christmas fundraiser the Bills star organised in 2020, to raise money to buy toys for children hit hard by the pandemic.
The fundraiser's target had been $2,500, but its running tally passed $3million by the early hours of Tuesday.