▶ Watch Video: NFL player Damar Hamlin hospitalized in critical condition

The family of Damar Hamlin on Tuesday expressed gratitude for the outpouring of “love and support” shown toward the Buffalo Bills safety hours after the player suffered cardiac arrest during a game Monday night in Cincinnati. The Bills said the 24-year-old Hamlin is in critical condition.

“Your generosity and compassion mean the world to us,” Hamlin’s family wrote in a message posted on the Twitter account of the player’s marketing representative, Jordon Rooney. “Please keep Damar in your prayers.”

The family did not provide a specific medical update on Hamlin, but they thanked the first responders and medical staff at the University of Cincinnati Medical Center for their “exceptional care.”

Hamlin suffered cardiac arrest while tackling receiver Tee Higgins in the first quarter of a game against the Bengals. Medical staff restored his heartbeat on the field before he was taken away in an ambulance.

Hamlin may have suffered a “remarkably rare” condition when he collapsed on the field, CBS News medical contributor Dr. David Agus told “CBS Mornings.”

Video shows that after the hit, he stood up, took a few steps and fell to the ground. 

While it’s not yet clear what caused Hamlin’s heart to suddenly stop beating, Agus believes the player sustained blunt force trauma to his chest “in the exact right spot, at the exact right moment during his heartbeat,” which caused his heart to have an arrhythmia — “not beat effectively to push blood to the brain.”

Agus suspects Hamlin’s heart was in ventricular fibrillation.  

“What we know with commotio cordis, which is this condition, is that every minute you delay shocking them, resuscitating them, what happens is there’s an increase of 10% in mortality,” Agus said. “They started CPR right away, which is great. My hope is they were able to restore the heart rate soon enough to be able to get blood flow to the brain so there’s no damage there.”