Jagielka told evertonfc.com: "It hurt massively (not being in the team). I'd gone from someone who everyone loves to a nobody. I was beginning to doubt myself.
"I didn't know how to get into the team and what I was going to do when I was in it. When I did get in I played in different positions and was very frustrated.
"It was like being away from home. I'd left something that was second nature to me. I wondered if I could cut it. Then David Moyes had a word with me. He was very reassuring."
He added: "When I stayed in the team after Joe came back the manager didn't say anything. But it was like a big silent pat on the back. He's very clever with his mannerisms.
"He keeps you guarded by not saying much and letting you decide what he's thinking. It's a clever way of doing things.
"People will understand what I mean when I say Neil Warnock's a one-off. He wouldn't do the arm-around-the-shoulder thing but he was a father figure to me. He looked after me. He knew I'd never let him down. I hope David Moyes will come to feel the same way about me."