Doctors have described Damar Hamlin's neurological function as "excellent" as the Buffalo Bills safety continues to make progress in his recovery after being resuscitated on the field during an NFL game at Cincinnati.
The Bills said the player continues to breathe on his own but remains in critical condition at the University of Cincinnati Medical Center.
Hamlin took a major step forward in his recovery on Friday when he was taken off a ventilator and was able to speak.
The 24-year-old also made a brief live video-conference appearance on Friday for his teammates, making several hand signs and saying, "Love you boys".
On Saturday, Hamlin posted a picture of himself on Instagram, describing the reaction from well-wishers as "overwhelming".
"When you put real love out into the world it comes back to you 3x's as much," he wrote in his post.
"The Love has been overwhelming, but I'm thankful for every single person that prayed for me and reached out.
"We brung the world back together behind this. If you know me you know this only gone make me stronger.
"On a long road keep praying for me!"
Hamlin went into cardiac arrest and his heart stopped on Monday night after making what appeared to be a routine tackle in the first quarter against the Bengals.
The game was initially suspended before officially being cancelled later in the week.
The Bills are planning to pay tribute to Hamlin and the first-responders and medical staff who treated the player when they close the season on Sunday (Monday AEDT) by hosting the New England Patriots.
The NFL will also show support for Hamlin during all week 18 games, which start on Saturday afternoon local time (Sunday AEDT), including a pre-game moment of support, painting Hamlin's No.3 on the 30-yard line, and wearing pre-game shirts bearing the message 'Love for Damar 3'.
The Bills will also wear '3' jersey patches.
On Saturday, the Steelers paid tribute to Hamlin, who is from the Pittsburgh area, by delivering toys, books and teaching supplies to a daycare centre where the player hosts an annual toy drive.
Fans, players and team owners have also made donations to Hamlin's Chasing M's Foundation, which had raised more than $US8.2 million ($A11.9m) by Saturday afternoon local time.
- with PA