Lehigh Police Chief Edward Shupp said officers responded to an emergency call from a college dorm room about an unresponsive male at 7:20 a.m. Sunday.
The man, identified as Garrett Reid, 29, was pronounced dead after efforts to revive him were unsuccessful.
"There were no suspicious activities," Shupp said.
"It's a tough morning for all of us in the Eagles family," Eagles General Manager Howie Roseman told reporters. "Garrett grew up with this team and this makes this news even harder for us to process."
The younger Reid served jail time after a 2007 conviction for driving under the influence of controlled substances, recklessly driving his vehicle, exceeding the speed limit, running a red light and colliding with a vehicle.
He was later returned to jail after failing a drug test and fighting with another resident at a halfway house.
The Eagles said team owner Jeffrey Lurie's annual state-of-the-team address, set for Sunday, had been canceled.