The Schalke general manager insists the forward will soon be back amongst the goals after breaking the deadlock against the Gunners in the Champions League on Wednesday
The Netherlands international has only found the back of the net on three occasions in nine Bundesliga appearances this season, but the 42-year-old is confident that his fortunes will soon pick up.
"He has put himself under the right type of pressure," he told Bild.
"That goal against Arsenal will give him a boost. He'll score a lot more."
High-flying Schalke sit a mere four points behind table-toppers Bayern Munich in the Bundesliga after their latest 1-0 victory over Nurnberg, though the Bavarians have a game in hand.