"Hart has great potential for sure," he said in an exclusive interview with Sky Sports. "He very quickly confirmed his ability in the Manchester City team.
"English fans complained recently about players in this position. But England have had some great keepers and Hart is another one on this list.
"He is going in the right direction.
"Can we name him the best in the world? It is difficult question.
"You can find fantastic keepers in other leagues as well, for example (Iker) Casillas in Spain or (Gianluigi) Buffon in Serie A. They have kept their top form for a very long period.
"If Hart can do the same, he will have a real chance of becoming the best in the world."