Everton defender Lucas Digne is facing a lengthy spell on the sidelines as an ankle injury sustained in training requires surgery.
The France left-back was hurt in training this week and the damage is such he has already been booked in for an operation on Monday.
It is a significant blow to Toffees boss Carlo Ancelotti, who now has a big hole to fill in defence as the 27-year-old has been one of their most consistent performers over the last couple of years.
"Everton Football Club can confirm Lucas Digne has suffered an ankle ligament injury,"read a statement.
"The left-back was injured during a training session at USM Finch Farm this week.
"Digne is due to undergo surgery on Monday before commencing his rehabilitation under the care of the club's medical staff."
The Frenchman has missed only five Premier League matches since he joined the club in the summer of 2018 from Barcelona for £18m.
Ancelotti signed Niels Nkounkou in the summer following the retirement of Leighton Baines, but the 20-year-old has been restricted to just one Premier League appearance and three Carabao Cup ties so far.
He he has featured in just two Premier League squads as an unused substitute aside from that one start in the defeat at Newcastle on 1 November.
Other options open to Ancelotti include playing a centre-back, such as Mason Holgate, or a midfielder out of position, although the recent switch to 3-4-3 for Sunday’s win at Fulham may make the adaptation more straightforward with Alex Iwobi impressing as a right wing-back at Craven Cottage.
Digne could miss as many as 12 matches, including a Carabao Cup quarter-final against Manchester United, if claims in France of a two-month lay-off are accurate.
Meanwhile, Everton midfielder Andre Gomes admits he is still trying to get back to full fitness after his horrific fracture dislocation to his right ankle 12 months ago.
"The truth is, I am still trying to find my best feeling, to get fit, to get ready to be 100% for all the game," the Portugal international told Everton’s matchday programme ahead of Saturday’s visit of Leeds.
"In the past months, with the pandemic, it was hard for me physically.
"When we came back after the first lockdown, I had a really small injury in one place, then something else in another place, because I was trying to compensate coming from the big injury.
"I came from a big injury and tried to get in perfect shape and feel really good on the pitch and work on that.
"It is part of my job to do my best to get back in the side. It has been hard this season."