Huddersfield Town midfielder Philip Billing is expected to miss up to three months after picking up an injury during the Terriers' 2-0 loss at Swansea City.
The Dane was stretchered off after a pass from team-mate Rajiv Van La Parra struck his leg on the hour mark.
Tests showed that the 21-year-old damaged the lateral ligament complex of his right ankle and is expected to be out of action until late January.
Wagner comments on injury to 6'6'' midfielder
Speaking on the news, manager David Wagner said: “Phil has had surgery on his ankle today and we would all like to wish him a speedy recovery."
Looking ahead, the German insisted: “The focus now is to help him return fitter and stronger than before, so he is ready to help us for the rest of the Premier League season.”
Billing has been with the club for the entirety of his career, joining Huddersfield's youth academy at the age of 16, and has made a total of 42 appearances for in a Terriers shirt.
He has made nine appearances this season, with one goal in a 2-1 win over Rotherham United in the Carabao Cup. He had signed a new three-year deal prior to the season, keeping him at the John Smith's Stadium until at least 2020.
Billing joins three others on the sidelines
With the news of the young Dane being sidelined, he joins Jon Gorenc Stanković, Michael Hefele and Kasey Palmer in the medical room.
Stanković is recovering from a pre-season knee injury, Hefele is rehabbing an Achilles problem while Palmer is currently out of action with a hamstring problem.