EAST RUTHERFORD, NEW JERSEY - SEPTEMBER 11: Safety Damar Hamlin #3 of the Buffalo Bills watches from the sidelines during the NFL game against the Buffalo Bills at MetLife Stadium on September 11, 2023 in East Rutherford, New Jersey. The Jets defeated the Bills 22-16 in overtime. (Photo by Mike Stobe/Getty Images)
CNN  — 

Damar Hamlin completed his NFL comeback Sunday in Orchard Park, New York, as he participated in the opening kickoff in the Buffalo Bills’ game against the Miami Dolphins at Highmark Stadium.

The Bills safety is appearing in his first regular season NFL game since suffering a cardiac arrest on the field against the Cincinnati Bengals in January.

The 25-year-old Hamlin was on the inactive list for the Bills’ first three games of the season. Hamlin did play in Buffalo’s three preseason games.

Hamlin was fully cleared to resume football activities in April. By August, he was a full participant in preseason games and performed well – making three tackles in limited playing time, including a fourth-down tackle to force a turnover on downs, in the team’s first preseason game against the Indianapolis Colts.

Hamlin collapsed in January after making a tackle and taking a shot to the head and chest area. Medical professionals performed CPR when he lost his pulse and he needed to be revived through resuscitation and defibrillation. He was on a ventilator for days and spent more than a week in a Cincinnati hospital.

It was later determined that Hamlin’s cardiac arrest was caused by commotio cordis, which can occur when severe trauma to the chest disrupts the heart’s electrical charge and causes dangerous fibrillations (or abnormal heartbeats).