Liverpool’s record signing, Alexander Isak, is facing several months on the sidelines after undergoing surgery on an ankle injury that included a fractured fibula.

Isak sustained the injury as a result of a heavy challenge from Micky van de Ven while in the process of scoring in Liverpool’s 2-1 win against Tottenham on Saturday. The 26-year-old was helped off in considerable pain and MRI scans confirmed Liverpool’s initial fears of a serious problem.

The club have not placed a timescale on Isak’s recovery but the £125m striker had an operation on Monday and will be out for several months.

The extent of the injury is a devastating blow for Isak, who has endured a difficult start to his Liverpool career beset by fitness issues. He had to play catch-up at the start of the season for Arne Slot’s team after missing the majority of pre-season at Newcastle having effectively downed tools to force through an eventual British record transfer to Anfield. The Sweden international was then ruled out for almost a month with a groin injury suffered against Eintracht Frankfurt in the Champions League.

Isak’s goal against Spurs was only his second in the Premier League for Liverpool and his third in total and his first courtesy of an assist from Florian Wirtz, a combination Slot had hoped would elevate the reigning champions this season. There is surprise at Liverpool that Van de Ven’s challenge went unpunished by the referee, John Brooks, and the video assistant referee, Stuart Attwell, in a game in which Spurs had Xavi Simons and Cristian Romero sent off.

With Mohamed Salah away at the Africa Cup of Nations with Egypt and Cody Gakpo also out injured, Slot’s attacking options are stretched as a consequence of Isak’s injury. The forward is the second of Liverpool’s summer recruits to suffer a serious injury and long-term layoff. Young defender Giovanni Leoni is out for the remainder of the season having sustained an ACL injury on his debut against Southampton in the Carabao Cup in September.