The Belgian playmaker damaged his ligaments on Wednesday, sparking fears that he could be out for at least the remainder of 2018 and possibly the rest of the season.
However, De Bruyne has since undergone further tests in Barcelona and the injury is not thought to be as serious as first feared.
Belgian news outlet Het Laatste Nieuws reports that the 27-year-old will not need to undergo surgery on the problem and could be back in action within two months.
De Bruyne injured the same knee in 2016, forcing him to miss 12 matches on that occasion.
The PFA Player of the Year runner-up scored 12 goals and laid on 21 more for his teammates last season as City won the Premier League and EFL Cup double.