Rangers midfielder Ryan Jack will miss the rest of the season and the summer's European Championship with Scotland.
Ibrox manager Steven Gerrard says the 29-year-old will receive treatment to fix a persistent calf injury.
Jack, capped 10 times, is expected to return in time for pre-season training.
"It's bad news for him from a personal point of view and everyone connected with the Scottish game as I think he's been phenomenal for the national team," said Gerrard.
"He was very much looking forward to that, so it's sad news for him.
"But the good news is that we've found a solution and got to the bottom of the problem. All being well in terms of his rehab from the procedure that he will have next week, he should be due to return in pre-season at some stage."
Jack returned from a two-month absence in January but broke down again in February after seven more matches.
"I'm hugely disappointed for Ryan as he deserved to be part of our squad for Euro 2020," said Scotland manager Steve Clarke.
"His performances for Scotland have been excellent, not least in the play-off final against Serbia when I thought he was outstanding at the heart of our midfield.
"I know how disappointed he is to miss out on the run-in to a memorable season - both with Rangers and with the national team at a major tournament - but ultimately his long-term fitness is the most important objective for him now."
The news comes a day after Scotland forward Oli McBurnie was ruled out for the rest of Sheffield United's season after breaking his foot.
Clarke also has concerns over the fitness of Arsenal defender Kieran Tierney, who is currently sidelined by a knee injury.
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