Arsenal have announced defender Takehiro Tomiyasu will miss the rest of the season with a serious knee injury.
Tomiyasu limped off in the ninth minute of the Gunners' Europa League loss against Sporting Club de Portugal last Thursday.
And Mikel Arteta's side have confirmed he has suffered a 'significant knee injury' which ends his campaign.
The club said in a statement on their website: 'Following his substitution during last Thursday’s Europa League match, subsequent assessments have confirmed that Takehiro Tomiyasu sustained a significant injury to his right knee.
'Tomi has had successful surgery in London on Tuesday and will be ruled out for the remainder of this season.