Clarke believes Suarez has the desire and belief that seperates the great players from the good.
"With any top player the mentality is always that bit stronger. That's what separates them," said the assistant manager.
"There are a lot of good players at this level and the really, really top ones have got that mental edge that drives them on all the time and produces the kind of performances that we've had from Luis so far.
"He's very grounded. He comes back in on Monday morning and works as hard as ever in training, he upsets all the defenders, scores a couple of goals and that's what he's all about.
"He trains like he plays - absolutely, every day. He loves to be playing football and that's a great thing."