Scotland's Huw Jones could be sidelined for five months after tearing a hamstring.
The 23-year-old centre has been ruled out of contention for the British and Irish Lions summer tour, as well as Scotland's.
Jones suffered the injury during Scotland's victory over Italy at the weekend.
A statement from his South Africa-based club, Stormers, read: "Huw Jones has torn his hamstring playing for Scotland in the Six Nations and will undergo surgery in London.
"This means that Jones will not be able to train for four to five months as he joins fellow Stormers midfielders Juan de Jongh and Damian de Allende on the sidelines."
Edinburgh-born Jones is due to join Glasgow in the summer and faces a battle to be fit for the start of next season.