Gray was in conversation with Sky Sports presenter and non-executive director David Jones, who is interviewing former players during the postponement of League One fixtures.
The former England international burst onto the scene for his hometown club in the early 90’s, but revealed that manager Mick Buxton had tried to bring his Sunderland career to a swift and early halt.
The arrival of Reid transformed his fortunes, as he went on to become a vital figure in the club’s rise to the upper echelons of the Premier League.
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“[Mick Buxton] was probably the manager who throughout all my career, I just didn't see eye-to-eye with,” Gray told Jones.
“He didn't like my personality, my lifestyle.
“He tried to sell me a couple of times.
“Being as I was at the time, about 18-years-old, he said 'you're going to be leaving the club'.
“I just said 'no I'm not and I'm going to be staying here longer than you are.
“He didn't play me for five or six games then lost his job.
“I started playing every single week after that and the rest is history.
“Peter Reid gave us a pep-talk when he came in and just gave us a massive amount of confidence.
“Right from then, I thought, 'I love this guy'.
“He got the Sunderland people, what it was all about.”
Gray discussed his role in an exhilarating period for the club, and in particular, his partnership with winger Allan Johnston.
Johnston left the club in the summer before they returned to the Premier League, joining Rangers.
Gray admits it was one of the big regrets during his time at the club, alongside the narrow failure to qualify for Europe in the early 2000s.
“We were just in sync,” Gray said.
“That's one of my big regrets at Sunderland to be honest, that Allan didn't stay and play in the Premier League.
“He was such a talented player.
“I knew him from my Manchester United days, so it was brilliant when he signed.
“He knew what I was going to do, that I loved overlapping.
“When Alan had the ball 1-v-1 I knew what was coming, a stepover, chop it onto his right foot and into the area, either setting it up or scoring goals.
“We used to have a competition with Chris Makin and Nicky Summerbee on the other flank for assists and goals,” he added.
“That's what it was all about.
“Nick's right foot, I've never seen anyone apart from Beckham cross the ball like him.
“He wasn't the quickest or the most energetic but we forgave him that because for Kevin and Niall, he was an absolute dream.”
Gray made over 300 appearances for the club before his departure.