Scotland internationals Stuart Hogg and Jonny Gray are each facing four to six months out after undergoing surgery on respective shoulder and wrist injuries.
The duo's club, Glasgow Warriors, confirmed on Friday that both players had gone under the knife and are set to miss a considerable chunk of the 2017-18 season as a result.
Hogg - the player of the tournament in the 2017 Six Nations - had an underlying shoulder issue operated on after he was forced to return home early from the British and Irish Lions' tour of New Zealand due to a facial injury.
Lock Gray, meanwhile, was hurt on Scotland's summer tour.
It remains to be seen whether either man will recover in time to play a part in Scotland's November internationals.
Glasgow are also set to be without Ratu Tagive for six to nine months after the wing had surgery on a ruptured Achilles.
INJURY UPDATE | Jonny Gray, Stuart Hogg & Ratu Tagive have all successfully undergone surgery: https://t.co/WJxFFLQWxW-- Glasgow Warriors (@GlasgowWarriors) June 30, 2017