Paul Dummett says Alan Pardew told him he wasn't good enough to play for Newcastle United in the Premier League.
The defender has played 126 games for his hometown club since being given his debut by Pardew five years ago.
However, Pardew, now in charge of West Bromwich Albion, needed convincing that Dummett was good enough to represent United.
"I've had plenty of setbacks in my career with injuries, or with people saying 'you're not good enough'," said Dummett, who had loan spells at St Mirren and Gateshead earlier in his career.
"You get sent on loan and when you do, you have to prove yourself, and that's what I did when I was younger.
"I got told I wouldn't be good enough to play in the Premier League, or good enough to play in a certain manager's team.
"You've got to overcome that, have self-belief and believe you're good enough."
Dummett, now fully fit after recovering from a long-term hamstring problem, was determined to prove Pardew wrong.
"When I got told I wasn't good enough (by Pardew), I just said it was up to me to prove him wrong," Dummett told the matchday programme.
"As soon as I said that, he knew I had the right attitude, because he said 'that's the attitude I want to see from my players'.
"I've always had a good attitude with wanting to learn and wanting to get better, and that's probably why I'm still playing for Newcastle now.
"I was never the stand-out player when I was really young.
"Getting to the older ages, if you asked a lot of people who played in teams with me or the managers I had, they probably wouldn't have picked me to be the player who would go on to play for Newcastle and play the 100-odd games that I have now.
"I've always had that belief in myself and the confidence that I was good enough, and I had to prove to certain managers who didn't believe that.
"With the hard hard I've put in, it's probably why I'm still here now."
Dummett hopes to start this afternoon's Premier League home game against basement club Swansea City.
Newcastle are 13th in the table after taking seven points from their last four games.