Ziyech lasted just 30 minutes against Marcelo Bielsa’s men before coming off with a hamstring injury.
The 27-year-old, who moved from Ajax Amsterdam to Stamford Bridge in the summer, also missed the start of the season with a knee problem but has returned to impress for Lampard’s men.
Ziyech will sit out Chelsea’s final Champions League group stage game against Krasnodar at Stamford Bridge on Tuesday but Lampard remains optimistic that Ziyech will soon be available again for selection.
“He came to us at the back end of last season and trained a lot,” Lampard said of Ziyech ahead of the game against the Russians.
“The injury [in pre-season] was disappointing and he missed some weeks, but straightaway he showed his intensity to work in the gym and on the training pitches as soon as he was back, and that was why he hit the ground running when he came into the team.
“I hope this is a minor injury. The feeling he had since the game is that it doesn’t feel too bad, which I’m hoping means we’ll be talking a couple of weeks, but we will wait for the scan.
“I’m not worried too much, he’s a fit lad, and he’s shown he will be an important player for us.”
Ziyech has made 12 appearances and scored twice for Chelsea this season.
