He has to have medical clearance, which means his grafts are deemed medically healthy as well as his surgical sites. His rehab started with walking, then more walking, and then more walking. He probably started running, then eventually tried rolling around. Just a guess, but if he has been training those new lungs the way he should he is probably in the best cardiovascular shape. He takes immunosupression medications which means he is safer wrestling on a clean wrestling mat versus digging in dirt gardening in his back yard.
I am excited for him. He isn't going to be a 23 year old world class athlete, but he is a double lung transplant recipient going out on a stage to complete. God bless him, and go Ben go.