Arsenal forward Gabriel Jesus will have an operation on his left knee after sustaining an anterior cruciate ligament injury.
Jesus, 27, was taken off on a stretcher during Sunday's FA Cup third round defeat by Manchester United at Emirates Stadium.
The Brazilian has made 27 appearances across all competitions this season, scoring seven goals.
"Gabriel Jesus has received extensive assessments, scans and specialist reviews which have confirmed an injury to the anterior cruciate ligament in his left knee," Arsenal said in a statement.
"Gabby will undergo surgery in the coming days and will soon begin his recovery and rehabilitation programme.