Racing Métro have confirmed that Ireland international Jonny Sexton suffered a broken jaw in Saturday's Top 14 clash with Toulon on Saturday night.
Craig Burden was sent to the sin bin for his late tackle on Sexton 15 minutes into the game.
The Irish fly-half continued to play and kicked two conversions after the hit, but was eventually brought off after 49 minutes.
A scan yesterday revealed the extent of the injury and the Paris side’s medical team have indicated it will take 4-6 weeks to heal.
The news will come as a blow to Ireland coach Joe Schmidt as it will leave the 29-year-old short of match fitness ahead of the November internationals.