Sissoko suffered an injury scare during Paris Saint-Germain's pre-season friendly against CSKA Moscow
The Mali international came off with five minutes remaining of the 2-2 draw in Austria.
L’Equipe reported that the former Juventus and Liverpool midfielder suffered a recurrence of the knee problem that caused him to sit out spells of last season.
Sissoko immediately left the club’s training camp to return to Paris for treatment.
The 27-year-old played 23 times for PSG last season, scoring twice.