The Argentine midfielder is regarded as one of the best playmakers in European football, but has been troubled by the off-pitch problems in recent seasons.
His representative Marcelo Simonian recently revealed that there were "several clubs" interested in the 25-year-old, something which has been reiterated this week.
"I can't answer the question of whether he will leave at the start of 2014," Simonian told Europa Calcio.
"I still haven't spoken to the Valencia president or even my client. There are a number of European sides who are interested in him, but I have to talk with Valencia and then Ever.
"How much would he cost? I don't know that right now either."
Manchester United have been linked with his services.