Having watched Peter Beardsley from the terraces as a youngster before eventually becoming his teammate and close friend, Clark believes the former England international stands above everyone else in the club's history, including Alan Shearer.
It is an opinion shaped by a remarkable personal journey, from idolising Beardsley during Kevin Keegan's first spell at St James' Park to sharing a dressing room with him when he returned to Newcastle in the 1990s.
"Peter Beardsley was your childhood hero," Clark was reminded.
"Yeah. Willie McFaul was who signed me as a 14-year-old," Clark said. "So Willie played a big part and he was the manager who would allow me to train. Peter was the superstar of that team. He'd just gone to the World Cup in Mexico. He was an unbelievable footballer.
"I'd watched him in the early '80s with the Kevin Keegan-inspired team, with Kevin Keegan, Chris Waddle, Peter Beardsley, Terry McDermott, that one promotion to the top level.
"When they tried to sign me, they mentioned that to Peter, and Peter would come and chat to me on a regular basis, give me football boots. He had a sponsorship deal with Puma, so here was my hero who I was watching, chatting to us and giving us boots. It was just unbelievable.
"And then in the '90s, when he came back to sign for us and I had the opportunity to play alongside him, it was like a dream come true, really."
For Clark, that experience of watching Beardsley as a supporter and subsequently playing alongside him gives his assessment particular significance. Newcastle have enjoyed some outstanding players throughout their history, including another former teammate - Alan Shearer, but his choice is unequivocal.
Clark continued, speaking with Football Presse: "Newcastle United's had some unbelievable footballers, top, top level. But in my opinion, and both from a fan's point of view but then being lucky enough to play alongside him, Peter would be the best player to have ever worn a black and white strip, in my opinion."
The comparison with Shearer inevitably follows. The former Newcastle captain remains the club's record goalscorer, but Clark makes a distinction between the two rather than diminishing either player's contribution.
"Different types. Alan was the out-and-out goalscorer, the leader. Peter was just something that could do – he was a magician.
"Peter, if you remember, to the Mexico World Cup, England didn't start particularly well and they changed things and the late, great Sir Bobby Robson brought Peter into the team. Peter was a number 10 before the number 10 rule was even invented and he played just off Gary Lineker, and I got the hat-trick in that final group game, and things just took off from there, really.
"And then obviously in Italia '90 as well, it was the same thing. So people will always say that because you can never look past Alan's goalscoring record and what he was as a famous number nine at the club. And that's not to diminish what he'd done, but I think in terms of the general – no way, no way. Difficult to put anyone ahead of Peter."
Clark's admiration has never been a secret to Beardsley himself, although he admits the former Newcastle forward was never particularly comfortable receiving such praise.
"I tell him, yeah, I used to, but he was so humble. He never really accepted it.
"We still see a lot of each other now, the old lads, and speak to Peter quite regular. So, yeah, I think a lot of the lads feel the same, especially the ones who were lucky enough to play alongside him as well.
"And obviously I had the added bonus of watching him be part of a promotion-winning team in the '80s as well. So I've seen it from both angles, really."
There is another aspect of Beardsley's character that Clark believes deserves greater recognition. Despite his achievements at the highest level, he remains deeply connected to football throughout the North East, regularly attending matches well below the professional game.
Asked about Beardsley's involvement with Newcastle nowadays, Clark expresses disappointment that someone with his experience is not more involved in football.
"Not so much. Still goes as a fan. He's obviously a Geordie, not involved in football, which is a crying shame, really, for someone of his stature and what he'd achieved in the game."
Clark does not believe that lack of involvement reflects a loss of enthusiasm on Beardsley's part.
"No, I don't think it's from Peter's point of view. Peter's very much like myself. I've heard about Peter and seen Peter going to local grassroots games, local non-league games. Peter loves football. He loves the North East football.
"He goes to support the non-league teams. He's there every time, whichever level of sport, not just Premier League or international. He'll go and watch non-league teams, grassroots. He loves football as well."
Clark believes those experiences could be invaluable to younger footballers, particularly in an era when the demands and scrutiny surrounding professional players have changed considerably.
"When there's people like him who have still got so much to offer from his experiences, even just from a communication point of view, to sit down and have mentorships with players to help them understand the pitfalls of certainly modern-day football, because you're all in the public eye.
"Even though there wasn't the media attention when Peter was playing, because Peter was so good and so highly thought of, he still had a lot of media attention himself personally. So all that type of stuff and being able to handle football at the highest level, it would be great. So you never know."
For Clark, Beardsley's greatness is not simply a matter of nostalgia or the affection of a supporter who grew up watching his hero. He experienced the footballer's ability first-hand, shared the dressing room with him and remains close to him years later.
Shearer's goalscoring record will always provide a formidable argument, but Clark has made his choice. For him, Peter Beardsley is Newcastle United's greatest ever player.