“Further to being substituted during our match with Manchester United on Sunday, Gabriel Jesus has received extensive assessments, scans and specialist reviews which have confirmed that he has sustained an injury to the anterior cruciate ligament in his left knee,” Arsenal said in a statement on Tuesday night.

Gabriel Jesus' knee injury is “not looking good,” Arsenal manager Mikel Arteta said Tuesday. The Brazil striker was taken off after 40 minutes in Arsenal's FA Cup loss to Manchester United on Sunday.

Arsenal's Brazilian forward Gabriel Jesus is set for a lengthy spell on the sidelines after suffering what is suspected to be an anterior cruciate ligament (ACL) injury, according to British media reports on Tuesday.