The Belgium playmaker came off worst in a challenge with N’Golo Kante just two minutes into the second-half and hobbled off to be replaced by Phil Foden.
However, the loss of De Bruyne would be a huge blow to City’s hopes of winning European football’s premier club competition for the first time.
PSG host the runaway Premier League leaders on 28 April with the return leg at the Etihad Stadium just six days later.