Jamie Ritchie will miss Scotland's World Cup opener with Ireland despite joining up with the squad in Japan.
The forward belatedly joined his team-mates in Nagasaki after suffering a broken cheekbone against Georgia.
Edinburgh flanker Ritchie, 23, has since had a titanium plate inserted.
"We know some players can come back in less time than that, but we're going to aim for the Samoa game rather than Ireland," said Scotland head coach Gregor Townsend.
Ritchie's club-mate Magnus Bradbury, who was called up as a precautionary back-up, remains in Japan for now.
Townsend said: "Jamie had surgery on Monday, so he joined us on Thursday. He's still recovering from the operation and also jetlag.
"We expect him to resume training next week. He's unlikely to be available for the Ireland game but he will be back in full training after that."
Townsend was left with fitness concerns over five players after that 36-9 triumph over Georgia in the Dark Blues' World Cup send-off.
Ritchie was the most serious but there were also worries for Blair Kinghorn and Ben Toolis after both suffered head knocks, while forwards Blade Thomson and Jonny Gray limped off with hamstring problems.
There was further anxiety when prop Allan Dell later reported a hamstring issue of his own, but Townsend said the fact all six of his injury doubts are now set to play a part in the tournament is "a huge boost".
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