The Blues have lost Senegalese goalkeeper Edouard Mendy to the tournament but were handed a boost when Ziyech was not included in Halilhodzic's squad last month following a reported bust-up with the Morocco coach.
Ziyech has not played for his country since June and missed all six of their World Cup qualifiers in the autumn.
Asked about his omission after the game, Ziyech said: "I'm doing my job and trying to perform as best as I can. All the other stuff that's going around outside of football, it's not really important at the moment.
"At this point, I don't really care to be honest."