The Frenchman says that he would be willing to depart if the transfer fee can help the Spanish outfit reduce their estimated €450m (£388m) debt.
"I'm happy here but if there is a significant offer from a top club and I can help Valencia make money, then we would talk," Football Espana quotes him as saying.
"My future? [Sporting director] Braulio [Vazquez] has spoken to me and I know that Valencia want to renew for two more years. I'm happy here but for now the contract issue is only small.
"My focus is not on me, or the coach's future. For me there is no issue because at the moment there are other more important things."
Mathieu's current contract with Valencia runs out in June 2014.