Atletico Madrid president Enrique Cerezo has warned that reports confirming that Mexico international Hector Herrera will play for Los Colchoneros next season are premature.
There had been reports both in Portugal and Mexico indicating that 28-year-old Herrera had agreed to join Atleti after his contract with Porto runs down this summer, but Cerezo is coy on the subject.
"It's not true or false that Hector Herrera is going to play for Atletico Madrid," Cerezo said in an interview with ESPN's David Faitelson. "Right now I can't say anything because he's not an Atletico player, although we always want great players.
"Don't count your chickens before they hatch," he continued.
Cerezo stressed that Atletico manager Diego Simeone has total control over the ins and outs of club's signings and that he hadn't spoken with the Argentine about Herrera.
"I've not spoken with him about that player," Cerezo said.
"When there isn't even any contact and they say that he will be going to a team, [the media] created false expectations surrounding the player.
"Whilst a contract isn't signed, getting ahead of yourselves isn't good for us or you."
Atletico may well be in the market for a midfielder should Saul leave for Manchester United or Manchester City, who are both reported interested in signing him.
Herrera moved to Porto from Liga MX side Pachuca in June 2013 in what was a record sale to for a Mexican club to a European institution at the time.
The midfielder has been quiet about his future, although Pachuca president Jesus Martinez has said that his dream would be to see former player Hirving Lozano at Manchester United and Herrera at Atletico this summer.
Should Herrera leave Porto without signing a new deal, as appears likely, the Mexican club would lose its sell-on percentage.
"It's a painful topic for us because we had a percentage of his transfer and the fact that he may go on a free means we lose that percentage," Pachuca sporting director Marco Garces told ESPN recently. "On the other hand, we'd love to see [Herrera] in one of the leagues that are watched more and that are more competitive, like the Spanish or English leagues and to see one of our home-grown products there."
Aside from Atletico, Herrera has been linked with Inter Milan, Arsenal, Roma and Lyon this year.