Sacked Napoli coach Maurizio Sarri admits Dries Mertens has made a fool of him.
Sarri is in talks with Chelsea to succeed Antonio as manager - and is understood to have recommended Mertens among a raft of potential additions to the Blues' top brass.
Sarri has revealed his admiration for Mertens after being asked to compare his work with the Belgium international and Gonzalo Higuain, now of Juventus, at Napoli.
"They are both satisfying things," said Sarri. "Bringing a player to break the goal scoring record is gratifying but at the base of it is a world class player.
"Gonzalo is world class, you just have to get the best from him.
"Dries is another phenomenal player and if he's doing well as a centre-forward it means it was our mistake that we only realised a few years late.
"After only a month in the position he became a natural centre-forward so we've all made a mistake in evaluating him.
"All his coaches, myself included, all thought he was a phenomenal player off the bench to change a match. With the right opportunity he proved us all to be fools!"
If they firm up their interest, Chelsea can sign 31 year-old Mertens for £28m.