Schalke 04's Holland striker Klaas-Jan Huntelaar is an injury doubt for Wednesday's Champions League play-off, first-leg tie at home to Greek side PAOK after injuring his right knee.
Huntelaar, who scored twice last weekend in the 3-3 draw at home to Hamburg, injured the knee in a first-half clash with Wolfsburg goalkeeper Diego Benaglio as Schalke lost 4-0 on Saturday in the Bundesliga.
"It looks like a medial ligament injury, I have to wait and see what the test results are on Sunday," said 30-year-old Huntelaar, who has scored 49 goals in 84 league games for Schalke.
Schalke coach Jens Keller admitted Huntelaar is doubtful for Wednesday's European tie.
"It does not look good," said Keller before calling extra training on Sunday in the wake of his team's rout.
After Metalist Kharkiv were thrown out of the Champions League by European's governing body UEFA for match-fixing last week, PAOK replaced the Ukrainians in the play-off.