The Spanish club are being linked to the signature of United winger Facundo Pellistri.
The Uruguayan, who is at the Copa America with his teammates, has struggled at Old Trafford.
"He would be a very important player," Pezzonalo told radio station Carve Deportiva.
"We talked about many names (with the sports management) and one of them, without a doubt, is him.
"I think it could benefit him a lot to be with us, although there are financial details that can or cannot be given. We know that it is not easy for us. I love him, but I have not dared to call him because I want him to give his best with the national team, although I suppose his representative will have sent it to him.
"Arriving at a team like ours in the pre-season, adapting well to the group, knowing that he comes to an intense, dynamic, vertical team when he goes outside… he can show off a lot when stepping into the area."