Kieran Richardson has admitted that his career might have 'gone off the rails' had it not been for Roy Keane.
Richardson linked up with his former Manchester United captain Keane at Sunderland in the summer of 2007 but a serious back injury kept him sidelined for several months.
The midfielder accepts that it was a difficult period but recalls how his manager helped him rediscover his best form.
"It was the first time I had ever been injured and mentally I found it difficult," Richardson said in The People.
"And at the end of last season, Roy Keane told me he wanted more from me. The talk he gave me inspired me so much - I came back slim, trim and ripped up.
"And everything has continued since then. It was a kick up the backside most definitely. He said 'You are not fulfilling your potential, you have so much more to give'.
"It was what I needed, he gave it to me and it made me hungrier. When Roy Keane talks, you listen.
"I want to thank him, because if it wasn't for that talk my career might have gone off the rails."
Keane stood down as Black Cats boss earlier this month following a poor run of results but Richardson believes he deserves praise for what he achieved with the club.
"He's got a massive presence, he was a great player and was a very good manager for Sunderland," said Richardson.
"He got the club promoted to the Premier League after they were bottom when he arrived and he sustained us in the Premier League, so he hasn't done anything wrong."