Ronaldo moved to Madrid from Manchester United in 2009 and, in addition to a host of individual awards, has won La Liga, the Champions League and two Copa del Rey titles.
However, it is understood that the attacker is keen on a return to England after becoming frustrated with Madrid's transfer business over the last couple of windows.
"My impression is he is fed up with the policy of the current president," Calderon told talkSPORT.
"When he came to Real Madrid with Arjen Robben he thought he would be a good colleague for him in the team but then Robben was sold.
"Two years ago it was Gonzalo Higuain sold and he didn't like that. Last year he thought it was a mistake to let Mesut Ozil leave and the last straw was selling Xabi Alonso and Angel Di Maria this summer."
Former club United are said to be preparing a big-money move for Ronaldo next summer.