McKay put in a stunning performance during the club's Scottish Cup semi-final tie.
The 21-year-old was arguably the Light Blues' man of the match during their Scottish Cup semi-final on Sunday, and scored an astonishing goal to edge the Scottish Championship side back in front during the early stages of extra-time.
But Warburton has been watching performances like that all season from the youngster, and suggested that he has the potential to go a very long way in the game.
"Barrie has just turned 21, he was out on loan at a couple of smaller clubs and from day one he has been outstanding," he told the Evening Times.
"He is technically gifted, rapid, one of the quickest players at the club. He reminds me of the likes of Eddie Gray, that type of Scottish winger.
"He has got every trick in the book and he will get better and better.
"There is still loads of development to come from him but [I am] very, very impressed. I am pleased for Barrie."
While McKay's season may ultimately be defined by that one moment at Hampden Park - much like Gray's career arguably was with his stunning solo goal for Leeds against Burnley in 1970 often overshadowing just how talented a winger he actually was for a prolonged period of time - he has been a key part of the Gers' success for most of the campaign.
He has scored five league goals and contributed eight assists to help the side power their way to the title and promotion to the Scottish Premiership.
And his performance against their Old Firm foes at the National Stadium provided a glimpse of what he may be able to do in the top flight next season, and his manager is clearly confident that he has the potential to one day find himself considered as one of the finest wingers in the game.