Franco Di Santo's Schalke debut ended in disappointment as the Bundesliga side were held to a goalless draw by Porto.
The Argentine striker signed a four-year deal on Saturday after the Gelsenkirchen club activated a contract clause to end his spell with Werder Bremen.
However, Di Santo was unable to find a way past goalkeeper Iker Casillas, or second-half replacement Helton, in Monday's low-key affair in Gutersloh.
Casillas had to be alert early on as Klaas-Jan Huntelaar met a Leon Goretzka delivery and tested the Spanish stopper with a neat volley, before Alex Sandro hit the post at the other end.
Goretzka himself then had a chance to open the scoring but saw his effort blocked by a defender, and an outstretched Di Santo failed to guide the ball on target for Schalke just short of the interval.
Porto started the second half brightly, with both Ruben Neves and Andre Andre seeing attempts saved, but Schalke were soon causing problems once again.
Di Santo teed up Huntelaar nicely two minutes from the hour, but the Dutch striker fired straight at substitute keeper Helton, and a raft of subsequent changes disrupted the flow of the match as it approached its conclusion.
