Brock Lesnar will have to be medically cleared to compete at WWE SummerSlam following his UFC 200 fight in accordance with the New York State Athletic Commission which oversees both MMA and Pro Wrestling in the state of New York.
A NYSAC representative Laz Benitez issued the following statement to LAW radio today noting:
"Potential participation by Mr. Lesnar in an August WWE event would depend on his medical fitness and physical condition at the time of the professional wrestling show. No person is allowed to participate in a professional wrestling exhibition in New York State until he or she is cleared as medically fit to do so by a New York State licensed physician."
If Lesnar suffers any injuries during his July fight at UFC 200 then there could be a high chance he won't be able to compete at SummerSlam.