If he can bring his Avatar Fighter with him.. (Geroge) I say Magoo by K.O. 1 RD [I take it, Liston might not be his fav fighter]
Liston stops Foreman. Liston threw much straighter punchers right down the pipe as well as having strength/power equal to foreman. Liston had the better boxing skills and he would really have alot of success with a body attack against foreman.