Hamlin has been a healthy scratch for the Bills' first three games due to the number of defensive backs and special teams members on the roster but has fully participated in practices since late in organized team activities. He participated in all three preseason games.
Poyer was ruled out Friday with a knee injury, which he suffered in the Bills' 37-3 win over the Washington Commanders last week. The injury led Poyer to miss the entire week of practice.
Backup safety Taylor Rapp, a free agent addition this offseason, is expected to start in Poyer's place alongside veteran safety Micah Hyde, who is also dealing with a hamstring injury but did not carry an injury designation going into the game. Buffalo coach Sean McDermott described Poyer's injury on Thursday as "day-to-day."
Hamlin's role would be on special teams and as a backup alongside defensive back Cam Lewis. Hamlin started 13 games in place of Hyde last year after Hyde suffered a season-ending neck injury.
In his third NFL season after being drafted by the Bills in the sixth round in 2021, Hamlin has not played in a regular-season game since suffering cardiac arrest Jan. 2 during a contest against the Cincinnati Bengals. Hamlin and the Bills announced that he was physically cleared to return to football in the spring.
During training camp, Hamlin spoke about a desire to make his return privately but also wants to use his platform to help others. He dedicated time throughout the offseason to spreading the importance of CPR education and the use of AEDs.
"I wish I could do this process under a rock ... just to myself and pop out whenever I felt like I was super, super duper, you know, ready to be a Pro Bowler," Hamlin said in July. "But I think it's power in being out here every day and doing my process in front of the world, and I always wanted to stand for something bigger than myself. It was my goal my whole life."