Ziyech was subbed off in the second half against Brighton on Saturday.
The Moroccan suffered a knee injury that has to be assessed.
Frank Lampard didn’t speak to the media after Chelsea’s pre-season 1-1 draw against Brighton which was marred by Hakim Ziyech’s injury.
However, as per the club’s official website: “After the game Lampard described it [Ziyech’s injury] as a little twist to the knee that will be looked at.”
The Moroccan was instrumental in creating the Blues’ goal against the Seagulls on Saturday with the 27-year-old’s cross leading to Timo Werner scoring in the fourth minute.