Celtic boss Ronny Deila says keeping his best players will take priority over acquisitions in the transfer window.
Chelsea striker Fernando Torres is understood to be set for a return to Atletico Madrid, according to Sky sources.
Navas has been heavily linked with a 10million euro move to Real Madrid among several other teams following his impressive exploits at the World Cup but, despite speculation that a move to the Bernabeu has already been finalised, nothing yet has been officially confirmed.
And Mendilibar, who took over at Levante this summer, does not have any more insight to give on the situation either.
He told Marca: "Nobody has told me anything about Keylor. He's still ours.
"I don't know him personally, but they tell me he's a great professional. The teams that you're hearing about, Bayern, Madrid...they are the best in the world. It's close to the date for his return and I only hope that things are resolved before then."