Rangers announced on Tuesday that top scorer Alfredo Morelos would be out for the rest of the Scottish Premiership season with a thigh injury that he picked up on international duty with Colombia.
The Scottish champions — facing an uphill task to hold on to their title — said the 25-year-old would return to training in pre-season.
“Following an injury sustained whilst on international duty with Colombia, Alfredo Morelos has undergone surgery to his thigh,” said a statement from the Ibrox club.
“Our medical team are pleased with the outcome of the operation and his rehabilitation programme is under way.”
The absence of the striker, who has scored 18 goals this season, will be a blow to Rangers, who trail Glasgow rivals Celtic by six points in the league with just six games to go.
Rangers also meet Celtic in the Scottish Cup semi-finals later this month and are into the last eight of the Europa League, where they face Portuguese side Braga.