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.

After a year away from the sport and with his broadcast career seemingly suffering a setback, Drew Brees teased a potential NFL return on Sunday.

Future Hall of Famer Brees posted on Twitter that he was "undecided" on his future amid reports of his time as an analyst for NBC coming to an end.

He wrote: "Despite speculation from media about my future this fall, I’m currently undecided.

"I may work for NBC, I may play football again, I may focus on business and philanthropy, I may train for the pickleball tour, senior golf tour, coach my kids or all of the above. I'll let you know."

Brees called it a career after the 2020 season - his 15th with the New Orleans Saints - and, while the competitive fire may still burn for an all-time great, the numbers suggest the correct course of action for the 43-year-old would be to stay retired.

Unlike Tom Brady, who swiftly unretired 40 days after announcing his decision to quit in the wake of one of the best seasons of his storied career, Brees endured one of his most underwhelming campaigns in 2020.

Brees remained extremely accurate, completing 70.5 per cent of his passes and delivering an accurate, well-thrown ball on 81.1 per cent of pass attempts.

However, he averaged only 6.41 air yards per attempt, the fourth-fewest among quarterbacks to attempt at least 50 passes.

His 31 completions of 20 yards or more were fewer than that of then-San Francisco 49ers backup Nick Mullens (33). Brees attempted just 21 passes of 21 air yards or more, illustrating an inability to push the ball downfield as his arm strength faded in the final years of his career.

Were Brees to make a comeback, he may not be able to do so with the Saints, who re-signed Jameis Winston to a two-year deal this offseason.

Saints head coach Dennis Allen said of Brees' tweet about a possible comeback: "I think it was a comment made in jest, and we certainly haven't had any conversations in that regard."

Given the age and the numbers from his most recent season, talk of a Brees return is indeed tough to take seriously.

Drew Brees is a "legend" who will be sorely missed after announcing his retirement, fellow New Orleans favourite Zion Williamson said. 

Brees called time on his glittering 20-year NFL career on Sunday, with glowing tributes pouring in for the quarterback. 

And Pelicans star Williamson, fresh from a 135-115 win over the Los Angeles Clippers, praised someone whose welcoming words have stuck with him. 

Williamson was the top pick in the 2019 NBA Draft and received a special message from Brees, who has had a lasting impact on the 20-year-old.

"He's a legend in the game, I think everybody knows that he's a legend," said Williamson, who is 22 years Brees' junior. 

"He gave his heart and soul to the game. I know a lot of people are sad to see him go. 

"Drew told me I think the truest thing anybody has ever told me, my first game in New Orleans – you love your city, they'll love you right back. 

"Whenever new people come and visit, that's the same thing I tell them. That's the kind of influence he's had on me." 

Brees is a 13-time Pro Bowler and was MVP in the Saints' Super Bowl win over the Indianapolis Colts in February 2010. 

The 42-year-old retires as the all-time leader in passing completions (7,142) and passing yards (80,358).

Drew Brees has called time on his remarkable NFL career, announcing his retirement after 20 seasons.