PROVIDENCE, R.I. (WPRI) — Doctors are weighing in on what may have happened to a Buffalo Bills player who collapsed mid-game Monday, and what the possible path forward is for his recovery.

Buffalo defensive back Damar Hamlin was listed in critical condition early Tuesday after the Bills said his heart stopped following a tackle.

Hamlin was struck in the chest by a Cincinnati Bengals player before getting up, taking a few steps and collapsing on the ground.

The 24-year-old was given medical treatment, including CPR, on the field for nearly 20 minutes before being rushed to a nearby hospital.

Dr. Daniel Philbin, director of clinical cardiac electrophysiology at the Lifespan Cardiovascular Institute, tells 12 News it’s challenging to know exactly what happened with the limited medical information that’s available.

Philbin said that, based on what was observed on the field, he believes it could be a phenomenon called “commotio cordis” that led to Hamlin’s cardiac arrest.

“The trauma that he took … he had a pretty solid hit to the chest,” Philbin said. “It would have been surprising, in a person who is otherwise healthy and athletic, to have another reason to arrest.”

Philbin said commotio cordis is a “rare, but known way” for even a relatively mild blow to the chest to cause a sudden arrest. He said it’s caused by the timing of the blow in the cardiac cycle, which can cause a small electrical change.

“If it’s transmitted to the heart, at just the wrong moment, it really is within literally milliseconds,” he said. “If it’s within the wrong time of the cardiac cycle when it’s vulnerable, it disorganizes the heart rhythm completely.”

Philbin said what’s unusual is that Hamlin got up after the tackle, seemingly OK, but then collapsed seconds later.

He added that, since medical professionals administered CPR quickly on the field, Hamlin’s chances of survival grew. Still, there are several other factors in play.

“The shorter the time between the collapse and a defibrillation from a defibrillator, typically, the better people do,” Philbin added.

Philbin said the 24 to 48 hours following the incident will be telling, and it’s not clear what it could mean for Hamlin’s potential return to football.

“That’s a highly variable situation from individual to individual,” Philbin said. “He was not unattended for very long, he was treated very rapidly and provided the good chest compressions that were given, and the shock was delivered early.”

“His prognosis for a meaningful neurologic recovery, actually, from what I’ve seen appears to be pretty good,” he continued.

The Bills released a statement on Twitter Tuesday, stating that Hamlin spent Monday night in the intensive care unit and remained there in critical condition at the University of Cincinnati Medical Center.

“We are grateful and thankful for the outpouring of support we have received thus far,” the team wrote.