Manchester City suffered an injury blow during the Champions League Match Day 2 clash against Hoffenheim in Germany on Tuesday.
Central midfielder Ilkay Gundogan had to be taken off for Bernardo Silva on 68 minutes after what appeared to be a hamstring problem.
The midfielder of Turkish origin was holding his hamstring as he was taken off against the Bundesliga outfit.
Gundogan had started the game for City before being forced off.
The scores were tied at 1-1 when he was taken off.
The Citizens will be hoping the 27-year-old is not out for a lengthy period of time as he has spent extensive time on the sidelines due to injuries since joining the club.
Gundogan had his first season at the club disrupted by the recurrence of a serious knee injury.
The midfielder played an important role in City winning the Premier League last season after recovering.
Gundogan helped the Manchester based outfit to the league and Carabao Cup double in 2018, making 48 appearances in all competitions and scoring six times.