Coloccini admits the Dutch destroyer is one of the division's form players.
"I think we have a test every week, but Robin right now is on fire, he is unbelievable and we're going to have a tough job. We will have to do well to stop him scoring," he told the Sunday Sun.
"I don't know whether he is the best as there are a lot of good players. I don't know if he is the best, but of course, he is one of the best and we have to be careful."