The Wales international was left on the bench for Real Madrid’s final home game of the season on Sunday, a 2-0 defeat to Real Betis, and returned to the dressing room without acknowledging the fans at full-time.
Bale’s future has been the subject of much speculation since Zinedine Zidane returned to the Bernabeu bench, and the Frenchman did little to calm the waters post-match.
"I'm sorry he didn't get to play, but no one knows what will happen," said the coach.
"If I think a player doesn't fit in the team, I have to do what I think works best. No one can change what Bale has done for the team, but as a coach I have to live in the present."
When asked about the future of Bale and goalkeeper Keylor Navas, Zidane said: "I don't know if it's the last game for them or not. I don't know what's going to happen."
Bale arrived in Madrid for a record £85 million from Tottenham Hotspur six years ago, but ex-president Calderon is convinced that he will leave this summer.
"Zidane is not keen on him; it is a relationship that will come to an end," he told BBC Sport Wales.
"It seems it was his last game for Real Madrid. Zidane, last year when he left, he thought it was imperative to keep Ronaldo and to sell Bale and they decided not to do that.
"It seems it is impossible for him to be here... because of the coach and the relationship with the fans. They think he is not committed and that is a problem.
"The best thing for him is to move. He should take the opportunity if there is one."
Calderon suggested that the La Liga giants could be willing to make a financial sacrifice to get the 29-year-old off their books.
“Maybe he will go on loan,” he added. “It is a problem when the coach and player do not get along, you have to look at every option to find a solution.
"The problem is the salary; it is a high salary. He has not been lucky at Madrid since the beginning. Fans thought for the money he would be better than Cristiano and that was really impossible.
"It is a divorce that is difficult to solve. They will find a loan or a transfer for perhaps a low amount of money."
Real Madrid finished third in La Liga with 68 points, their lowest total in 17 years, as well as being knocked out of the Champions League by Ajax in the last 16.
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