Barcelona have announced that forward Martin Braithwaite is set to undergo knee surgery and faces a lengthy spell on the sidelines.

The Denmark international sustained a knee injury in the club’s 2-1 win against Getafe on August 29 and then missed Denmark’s World Cup qualifiers.

The La Liga club said in a statement that the 30-year-old had opted for surgery after the injury did not respond to conservative treatment.

Mundo Deportivo report that Braithwaite could be out of action for three to four months, another blow to Ronald Koeman’s squad with long-term absentees Sergio Agüero and Ousmane Dembélé already on the sidelines.