Prior to Brock Lesnar's return to UFC to face Daniel Cormier, the Beast will have to pass a series of drug tests and then he will be cleared to return to the octagon by January of next year if he is successful. He just recently took his first test after re-entering the pool on July 3rd.
Cormier has stressed that he refuses to face Lesnar unless he is 100% sure that the man is completely clean:
"Brock's got to be clean. I'm not going to fight him if he's not clean. We'll do USADA testing, and we'll do other testing. We'll do testing above USADA to make sure this man's clean, because I'm not going to fight him if he's cheating. I've done that on a number of occasions already (with others). I don't want to fight him if he's dirty, man. Do it the right way."