In this Aug. 30, 2006, file photo, former heavyweight boxing champion Mike Tyson spars during a training exhibition in Las Vegas. Tyson hasn’t announced any plans to return to the ring, though he did suggest on an Instagram post he might make himself available for 3 or 4-round exhibitions if the price was right. And already some people in Australia are talking about offering him $1 million to fight an exhibition against a rugby star or two. (AP Photo/Marlene Karas, File)