put (one) up against (someone)
To arrange for one to face off against someone in a competition. I want to put your daughter up against the national champion—I think she could hold her own. They're putting me up against the highest-ranked chess player in the state.
put someone up against someone
to place someone into competition with someone else. The coach put his best wrestler up against the champ from the other team. The varsity put themselves up against the alumni team in a game to benefit charity.