And the careers advice comes from the team-mate whose own career is entering the twilight zone.
Steven Thompson delivered the resounding vote of confidence in the 18-year-old after penning a deal that will see him end his career in Paisley.
And the veteran former Rangers striker is convinced McGinn's can surpass the potential he has shown in his first-team appearances so far.
"He has all the attributes necessary to become a top midfielder," said Thompson.
"He really does have the potential to go as far as he wants in the game.
"He as his feet on the ground and the fact that he comes from a big footballing family means that he has had a lot of sound advice. The thing about being at St Mirren is that he will get his chance to play.
"There is a lot of competition for places, especially in that midfield area, but he will get the opportunity to play in matches because he has shown already what he is capable of.
"He is an exciting talent. He played very well in our League Cup semi-final win over Celtic and experiences like that can only help him be a better player."
Saints take on Hibs this weekend in Paisley and Thompson doesn't believe St Mirren have left it too late to mount an assault up the table.
He said: "We think we are much better our league position, but you have to go out and prove that on the park.
"The team is feeling good and we're playing with confidence because of the results we've had.
"We might be second bottom, but there are only four points between us and Hibs who are in fourth, so it's not too late for us to kick on."