Gary Medel looks set for a spell on the sidelines after Inter confirmed on Tuesday the midfielder had suffered a knee injury during the Milan derby.
The Chile international returned from suspension to start the 2-2 draw at San Siro on Sunday, but had to be replaced shortly before half-time.
Following tests, Inter revealed Medel had damaged his lateral meniscus and would be monitored in the coming days.
He seems certain to miss Thursday's trip to Haopel Be'er Sheva in the Europa League, where a defeat would see Inter eliminated from the competition.
Medel could also be absent for the upcoming Serie A fixtures against Fiorentina and Napoli, two sides battling with Stefano Pioli's men for the European places.