The 32-year-old could leave Villarreal on a free transfer when his contract with the club expires at the end of the season.
“The renewal of the contract, in the next 15-20 days we will also talk about this with Villarreal,” his agent Horacio Gaggioli told Calciomercato.
“The hypothesis of a renewal cannot be ruled out, with the club we were agreed to talk at the end of November.
“However, Joan is playing at the highest level and many teams would want him.
“I know that Juventus is interested and in the summer there was an attractive offer that didn’t materialise, but there is also other interest.
“Schalke, Valencia, as well as some clubs in England, but obviously we won’t do anything until we have spoken with Villarreal.”