Update, Sunday Jan. 8 1:15 p.m. ET:
Buffalo Bills safety Damar Hamlin remains in the hospital after suffering cardiac arrest on the field on Monday, but his presence will be felt everywhere on Sunday as the NFL wraps up its final regular season games.
As players began rolling in to prep for the 1 p.m. ET games, one thing was obvious: Damar was on everyone's minds. Many of them wore Hamlin's Bills jersey as they walked into their respective locker rooms, sending him love before the stadium doors were even open.
Baltimore Ravens safety Geno Stone, who played youth football with Hamlin in the Pittsburgh area and ran track against him in high school, repped his childhood friend by wearing his jersey.
New York Jets cornerback Sauce Gardner, Cincinnati Bengals wide receiver Tyler Boyd and cornerback Cam Taylor-Britt wore Hamlin's jersey while they were warming up on the field.
And of course Bills players were all decked out in Hamlin gear.
Other players and coaches wore T-shirts honoring Hamlin during warmups.
Hamlin caught Bills quarterback Josh Allen wearing his jersey when the Bills tweeted a video, and was so thrilled that he had to post his thoughts.
Hamlin will be aware of it all. He has made remarkable progress since he collapsed on the field while the Bills played the Bengals on Monday. His breathing tube has been removed and he's talking and tweeting now. He FaceTimed with the Bills on Friday and told his teammates he loved them.
The NFL has also reportedly been working to get Hamlin's hospital room wired so he can watch the Bills play their final regular season game.
There have been several other tributes too. Teams are outlining the number 3 on their playing fields.
Sarah Taylor, the wife of Bengals head coach Zac Taylor, asked her kids' classmates if they wanted to make cards for Hamlin. That turned into 53 Cincinnati-area schools writing cards for Hamlin, who took delivery of all those cards Friday.
The ambulance at Highmark Stadium added a new Damar-themed decoration to their back windows.
Just under two hours before the early slate of games kicked off, Hamlin tweeted a video of the Bills running through the tunnel at Highmark Stadium, saying that he wished he could be there with them on Sunday. Even though Hamlin is not there physically, his teammates (as well as players around the league) will be carrying his fighting spirit with them during the game.
UPDATE: The Bills definitely brought Hamlin's fighting spirit with them onto the field against the New England Patriots. On the very first play of the game, Bills running back Nyheim Hines returned the kickoff for a touchdown. The stadium absolutely exploded, and Hamlin tweeted this from his hospital room:
Later oh, Hamlin took a break from watching the Bills game to chat with his best friend, Philadelphia Eagles running back Miles Sanders. And Hamlin was in great spirits.