Abou Diaby's injury curse struck again on Thursday when the Arsenal midfielder was ruled out for up to nine months after tearing the anterior cruciate ligament in his left knee.
The 26-year-old France midfielder suffered the injury in training on Wednesday and is due to undergo surgery.
"Abou Diaby injured his left knee in training on Wednesday and subsequent scans have confirmed that he has torn his anterior cruciate ligament," Arsenal said in a statement.
"Following consultations with specialists, Abou will undergo surgery to repair the injury in the near future. Abou is expected to be out for around eight to nine months.
"The thoughts and best wishes from everyone at Arsenal are with Abou, and we all wish him a successful recovery."
Diaby has been blighted by injuries ever since joining Arsenal from French club Auxerre in 2006.
He fractured and dislocated his ankle in May of that year and made only 27 league appearances over the following two seasons.
Things improved in the 2010-11 campaign, when he established himself in the Arsenal midfield and looked set to make a breakthrough with the French national team.
However, a string of injuries restricted him to just five appearances last season and he has played only 16 times in the current campaign.
Diaby's injury adds to Arsenal manager Arsene Wenger's problems in central midfield, with Jack Wilshere currently sidelined by an ankle problem.