The Dutchman is delighted with the form the Bundesliga side have shown since his comeback from injury, winning four games in a row, but knows the perils of becoming complacent
The Bundesliga side had not dropped a single point since the return of the Dutchman, who scored the winning goal in Schalke's 2-1 victory over Bayer Leverkusen at the weekend.
However, despite taking 12 points from their last four games, the 30-year-old has urged his side not to get carried away.
“When you win several games in a row everyone's always relaxed and satisfied,” the striker told the club’s official website. “We have to keep going now. The players have come closer together recently and are united.
“When you've been out a long time you're dying to play again. You appreciate how nice it is to be fit again. I feel good and I'm glad to be able to help the team.
“Our target is to finish at least fourth. We've always said that's the position we wanted. It has maximum priority.
“Despite or rather precisely because of our recent success we can't afford to be cocky now, though. We simply have to keep working the way we have been doing.”
Schalke lie in fourth spot, three points behind second-placed Leverkusen.