The ex-England creative talent spoke about Guiu’s impressive hat-trick in the Conference League against Shamrock Rovers.
He scored all three goals in the first half of a 5-1 romp, leading to fans calling for his inclusion in Premier League games.
“My thought with Mark Guiu is, how did Barcelona let him go?” Cole questioned on TNT Sports.
“When I watch him play, and he's 18 years of age, this kid, in two years'time could be an established, unbelievable No 9.
“I think he could go go all the way, because I watch him and and all the things that you can't teach he's already got.
“He knows when to go in the box, his instincts, his aggression, he's brave.
“He can brush up on all the other things in his game. And at 18, he's playing with a smile on his face, you know, I think Barcelona made a real, real mistake there.”