Defender Darragh Lenihan will likely miss the rest of Middlesbrough's Championship campaign following an operation on an ankle injury.
He last played in September's 2-1 win over Southampton, and has missed Boro's past eight league games.
Republic of Ireland centre-back Lenihan joined Boro from first professional club Blackburn Rovers in June 2022, and has since scored one goal in 53 games.
"Road to recovery begins today," the 29-year-old posted on social media.
"Gutted to be missing the rest of the season but I'll be helping the lads as best as I can from afar."
Lenihan has captained Boro on occasion, as he did at former club Rovers, and has four international caps.