The interview will air Thursday on the OWN network.
The once seven-time Tour de France winner has continuously denied using performance enhancing drugs in the past.
San Diego physical therapist Brian Wilson is not only a competitive cyclist and triathlete, but also trains other athletes.
Wilson said he won’t be surprised if Thursday’s interview reveals Armstrong was involved in doping.
“You kind of expect to see these unfolding more and more as drug testing gets more and more strict,” said Wilson.
Despite the disappointment Wilson believes the public will eventually forgive.
“There’s going to be that initial shock,” said Wilson. “But it should start to fade away and turn into forgiveness over time. It’s happened before in the past, some of the main cyclists out there have done this or had this issue, just none of them quite so prevalent.”
Sources close to Armstrong said he wants to get back into racing and he’s doing this to begin repairing his image.
“I feel like that would be a nice ending and a good exclamation point on genetic gifts,” said Wilson. “And being able to dial those in and really show that the talent, hard work and dedication can really bring you to the top without the aids of drugs.”
Prior to the Oprah interview on Monday, sources said Armstrong apologized to the staff at the Livestrong Cancer Foundation. Those sources did not say he admitted to using performance enhancing drugs.