Hakan Calhanoglu is out of Inter Milan's Champions League opener at Real Sociedad with a thigh injury, the Italian club said on Tuesday.
In a statement, Inter said that Turkey captain Calhanoglu would miss the trip to the Basque Country for Wednesday's Group D fixture due to a "left thigh strain".
The 29-year-old midfielder was on target from the penalty spot in Inter's thumping 5-1 win over local rivals AC Milan on Saturday which cemented their place at the top of Serie A.
Calhanoglu's absence could lead to a first start of the season for Italy international Davide Frattesi, who also scored against Milan.
Wing-back Juan Cuadrado is also out with a knee injury picked up on international duty with Colombia.