Inter Milan playmaker Wesley Sneijder has been diagnosed with a strained muscle in his right leg, ruling him out for about 20 days.
The Netherlands midfielder was injured during the pre-match warmup for Inter's 2-1 win over Cagliari in Serie A on Saturday.
Sneijder will miss Inter's Champions League match at Trabzonspor on Tuesday and could also sit out against CSKA Moscow two weeks later. Inter need just one point from the remaining two matches to reach the next round.
Defenders Lucio and Yuto Nagatomo, meanwhile, have recovered from injuries and were included in the squad for the trip to Turkey.