The 27-year-old moved to the Bernabeu for a then-world record fee of £86m in September 2013 and has gone on to score 49 times in 85 league appearances for the La Liga giants.
According to Spanish outlet Diario Gol, the striker has become increasingly unhappy in the Spanish capital over the last year, however, and is now seeking a move away at the earliest opportunity.
Perez is said to have promised Bale a new contract complete with a salary increase last year but the deal has failed to materialise, while the Welshman allegedly is "tired of living under the shadow" of Cristiano Ronaldo, whom he believes receives preferential treatment from Zidane.
"The Welsh international left the field very upset," a source told the publication. "He did not understand his replacement. He felt he had more merit to continue playing than Cristiano Ronaldo and [Karim] Benzema. But, again, he was the one to be sacrificed."
Manchester United are the strong favourites to sign Bale should he depart the Bernabeu next summer.