Garrett Reid, 29, died Sunday in a dorm room at Lehigh University in Bethlehem, Pa., where the Eagles conduct training camp. Andy Reid didn't speak on the specifics of his son's death but did acknowledge Garrett Reid's previous issues with drug addiction.
About 900 people, including NFL Commissioner Roger Goodell, attended Garrett Reid's funeral Tuesday.
Andy Reid rejoined the team Wednesday.
"I'm a very humble man standing before you," Reid said at the start of a media session Wednesday. "I'm humble because of the outpouring (of support)."
"It's a sad situation, it's one my son's been battling for a number of years," Reid said. "He got caught up in a bad situation that affects a lot of people. We understand that Garrett's at peace and in great hands. Whatever trials and tribulations he had here, he's in a better place."
Andy Reid said returning to the practice field was the right thing for him to do.
"I'm a football coach. That's what I do," he said. "I know my son wouldn't want it any other way."
The Eagles open their pre-season schedule Thursday in Philadelphia against the Pittsburgh Steelers.