It had been reported that both European giants were in talks with Valencia over a transfer, but Mathieu said that he has heard nothing of the speculation so far.
"Up until today, there has been no contact with Barcelona or with Bayern Munich," he told Cadena Cope. "Also, the decision will be made by Valencia, I am at 100% and after that it is up to the club.
"I cannot say anything because I have had no contact, I have a big contract here and I am happy at Valencia."
Mathieu joined Valencia in 2009.