Schalke sporting executive Horst Heldt expressed frustration with Klaas-Jan Huntelaar as the Netherlands international's goal drought continued in the 0-0 draw with Augsburg at the weekend.
Huntelaar missed the best chance of the game when he failed to capitalise on a Daniel Baier mistake early in the second half, and is now approaching 1,000 minutes without a Bundesliga goal.
Schalke now find themselves eight points behind fourth-placed Bayer Leverkusen with seven games remaining, and Heldt told reporters: "We lacked intelligence in the decisive moments. Klaas-Jan Huntelaar had the biggest chance, and you have to turn such situations into a goal.
"When you don't do that, you will not leave the pitch as the winner."
Schalke had experienced an upturn in form when Roberto Di Matteo took charge in October and helped to organise the defence, but they have struggled in attack since the winter break, with neither Huntelaar nor Eric Maxim Choupo-Mouting scoring in 2015.
The rest of the team have managed only nine goals in 10 Bundesliga games this year and Schalke have taken six points from their last seven games, which is likely to mean a failure to return to the Champions League next season.
Schalke youngster Max Meyer said after the Augsburg draw that bad luck could be the primary reason for the team's recent struggles.
"We can't be happy with just one point," he added. "We wanted more when we travelled here. We had good chances in the second half, and usually we would score and take the win. Maybe we lack luck right now."