Hamlin has been in a critical condition in hospital following the incident that took place during Monday’s NFL game against the Cincinnati Bengals.
The 24-year-old had CPR on the field after colliding with Bengals wide receiver Tee Higgins before being taken to the University of Cincinnati Medical Center.
Speaking to CNN outside the hospital, Hamlin’s uncle Dorrian Glenn said: “His heart had went out so they had to resuscitate him twice.
“They resuscitated him on the field before they brought him to the hospital and then they resuscitated him a second time when they got him to the hospital.
“I’m not a crier, but I’ve never cried so hard in my life. Just to know, like, my nephew basically died on the field and they brought him back to life.
“They sedated him just to give a better chance for him to just continue to heal better. We are just taking it day by day. It seems like he’s trending upwards in a positive way.”
Hamlin was said to be on a ventilator while sedated to help with his breathing.
Bills players and staff were seen praying together on the field as an ambulance took Hamlin to hospital.
His team-mates were given a standing ovation by fans and NFL commissioner Roger Goodell soon announced that the game had been postponed following the incident.
An NFL update confirmed the fixture will not be finished this week but added that the Bills’ clash against New England Patriots on Sunday is still scheduled to go ahead.
A statement said: “After speaking with both teams and NFLPA (NFL Players Association) leadership, NFL commissioner Roger Goodell informed the clubs today that the Bills-Bengals game will not be resumed this week.
“The NFL has made no decision regarding the possible resumption of the game at a later date. The league has not made any changes to the week 18 regular season schedule.”
There was an outpouring of emotion across the United States in response to the incident, with fans gathering outside the University of Cincinnati Medical Center to hold candlelit vigils for Hamlin.
His family in a statement expressed their “sincere gratitude for the love and support shown to Damar during this challenging time”, adding: “We are deeply moved by the prayers, kind words and donations from fans around the country.”
The incident sparked an astonishing surge in support for a charitable campaign set up by Hamlin two years ago to purchase toys for children in need.
Donations to the Chasing M’s Foundation Community Toy Drive had passed 6million US dollars (£5million) as of Wednesday lunchtime in Britain.
A message on the GoFundMe page said: “This fundraiser was initially established to support a toy drive for Damar’s community, sponsored by the Chasing M’s Foundation.
“However, it has received renewed support in light of Damar’s current battle and we can’t thank all of you enough. Your generosity and compassion mean the world to us.
“If you would like to show your support and contribute to Damar’s community initiatives and his current fight, this is the place to do so. This is the only current fund that is being used by the Hamlin Family. Again, thank you for your thoughts, prayers and generous support during this time.”
Messages of support for Hamlin have poured in following the incident.
Higgins offered his “prayers and thoughts” to Hamlin and his family and added on Twitter: “I’m praying that you pull through bro. Love.”
Buffalo are the only franchise to play in New York state and Eric Adams, the Mayor of New York City, said: “I’m asking all New Yorkers to join me in praying for Damar Hamlin, his family, his team-mates, and our brothers and sisters in Buffalo.”
Basketball star LeBron James also offered has prayers to Hamlin following the Los Angeles Lakers’ victory over the Charlotte Hornets on Monday night, saying: “I wish nothing but the best for that kid, for the city of Buffalo, the franchise of the Bills, the rest of the NFL and the Bengals who were playing in that game.”