Stones reckons Martinez didn't treat or coach him in the proper way at Goodison Park last season, leaving him feeling at rock bottom.
The England star claims Martinez never explained why he wasn't picking him and he said: “It was a tough period because I was doing everything right.
“I was being professional, I was carrying myself well. I wanted to do everything right, try to get in the team, how everyone should and fight my place.
“I felt I was doing everything I could and deserved to play and still wasn't. That's when I found it hard.
“It's probably a question you should have asked him at the time because he wasn't telling me."
Asked if felt he was getting the right advice about his defending, Stones replied: “Maybe not. Maybe things weren't just working out either.
“But I definitely believe that change is good. I felt it was the right time to move on and go and further different ambitions in my career and it was an opportunity that I couldn't turn down.
“Roberto had his style of play and kind of changed that towards the end of his career at Everton.
“He changed the whole style of the team and things weren't working out at that time, so you could say it wasn't the best decision.
“But that's football, he is the manager and he makes tough decisions. I felt it was right to move on to work under the best manager (Guardiola) in my eyes."