The 16-year-old forward has been much-talked about since making his debut for the club’s U20 side aged just 13, while he also trained with the first team under Brendan Rodgers.
Dembele is never far from the sport pages, especially over his future at international level with the player eligible for both England and Scotland.
The teenager has turned out for both countries at youth level but suggested his future lies with England following an Instagram post last month.
He said: “Looking forward to next season with the boys ENG16.”
It won’t be confirmed until he turns out for either side in an competitive match at senior level.
Yet, McNamara has noted doubts among the top teams.
He revealed that Manchester City and their peers have concerns about the player’s size.
“Dembele looks a talent, left foot and everything else,” he told Football Insider.
“All the clubs are looking at him, like Man Citys. I know other clubs mostly, Man City are like, ‘phwoar’ at 12, 13, 14 but now they’re like ‘nah, don’t think he’s going to do it’.
“He’s little, but he’s been that for a few years now, he’s been that same size when they were all younger so he was like a wee man but nowadays they’re bigger than him and he’s not moved.
“Don’t get me wrong, the player’s there but because he was a wee man at that age (13), he’s the exact same as he was roughly then – strong, powerful left foot, low centre of gravity, but there comes a time.
“My son’s 15 next month, at that age I was smaller, I’m not a big guy but I was tiny, small, skinny and I got released.”