The forward has been linked with a move to the European champions, with head coach Julen Lopetegui said to be keen on a reunion with a player he knows well from his time in charge of both Spain's Under-21 and senior side.
Alemany admits there is little Valencia can do to stop a move if Rodrigo's buyout clause is met, but he is confident the 27-year-old will snub a return to the club he joined as a youngster back in 2009.
"I'm not in contact with them [Real Madrid]," Alemany told BeIN SPORT when asked about Rodrigo, who scored 16 goals in LaLiga last season and equalised in the opening game of this term, against Atletico Madrid on Monday.
"If they offer €120million, there's nothing we can do, but Rodrigo seems to be very happy and motivated here.
"Rodrigo is very important for us and we want him to stay."
Alemany is also pessimistic about the prospect of bringing Goncalo Guedes back to the club on a permanent deal.
Valencia are said to have reserved the number seven shirt for the 21-year-old, who spent last term on loan at Mestalla from Paris Saint-Germain.
However, it seems negotiations over a deal are far from concluded, with PSG said to be looking to recoup €50m for the winger.
"His desire is to come, he's been an important player for the club and the fans, but we have the difficulty of both the team he belongs to and his quality," said Alemany.
"The price is very high, and we have to take into account our financial situation. We work to be prudent, we work for him to come, but we're ready in case he doesn't."
Valencia drew 1-1 in their opening encounter of the new season against Atletico Madrid and next face Espanyol on August 26.