Barkley has built himself a reputation as one of Europe's rising stars during his time at Everton.
And the 21-year-old has also made an impression on Warnock, with Barkley having spent a brief period on loan at Leeds from Everton.
"I'd say Ross Barkley for the small spell he spent at the club. Could see his ability from day one. Incredible player," he wrote on BeanBagSports when asked who his best ever Leeds team-mate was.
However, the 33-year-old rates youngsters Sam Byram, Lewis Cook and Alex Mowatt very highly, as well.
"For me at this moment it's Sam, Alex and Lewis," he said when asked who the most talented players at Elland Road are.
"I think they can play at the top of the continue to develop in the way they have so far," he added on midfielders Cook and Mowatt specifically.
When it came to Leeds goalkeeper Marco Silvestri, though, talk between Warnock and his fans turned from the Italian's football... to his hairstyle.
"Ha ha it's a shock every time he walks in with a new cut. Look out tomorrow he's sporting another new look."