"Dirk was a key player for us against Wigan but I think by the end of the season he will have proved himself to have been a key player for us all year," said Rafa Benitez.
"He is always a player with confidence. If he's not scoring goals himself, he just works harder, which is a solution to that problem.
"Now, he's scoring good goals. He might have ended up with three or four out there, and that has to be positive for the team."