Blackburn Rovers midfielder Sondre Tronstad will miss the rest of the season after undergoing a full anterior cruciate ligament reconstruction.
The 30-year-old Norwegian came off at half-time in the defeat by Bristol City on 24 February.
Rovers said Tronstad, who is out of contract this summer, "will have the full support of the club's medical department throughout his rehabilitation journey".
Michael O'Neill's men are 20th in the Championship, four points above the relegation zone.
- Latest Blackburn Rovers news, analysis and fan views
- Listen to Blackburn Rovers content on BBC Sounds