Santi Cazorla's fitness nightmare amounts to the worst injury Arsene Wenger has ever seen, but the Arsenal manager remains hopeful the popular playmaker can return to action next year.
The Spain international has not played since October 2016 due to Achilles tendonitis and had already spent long stretches on the sidelines prior to that.
Asked at a news conference before Saturday's north London derby if the 32-year-old's problems amount to one of the most serious fitness issues the manager has encountered during his long career in football, Wenger's response was unequivocal.
"Yes," he said. "Yes, it is the worst injury I have known, that started with a little pain and got worse and worse.
"I know how much Santi loves to play and to be out there every day. I feel really sorry for what happened to him because it's unbelievable.
"I told him to prepare as much as he can, I have not spoken to him recently. [But] I hope he comes back.
"That's why I left him out of the squad, hoping he will be back in January."
A more immediate return to regular action looms for Jack Wilshere, who could still prove useful to England coach Gareth Southgate, according to Wenger.
Questioned on what the 25-year-old needs to do to get back in the Gunners' first team, the manager said: "It's to keep fit and work hard, that's what he does.
"Slowly, I think he will get into the spirit of Southgate's game, the creative aspect of his game is a big asset for him. He's very close."