Everton have been dealt a significant blow after news emerged that the club lost a key player to an injury, with Lucas Digne suffering major damage to his ankle ligaments in a training session at Finch Farm on Thursday.

As is noted by Sky Sports, Digne has missed only five league matches since his £18m move from Barcelona two years ago, a testament to his vital role in Carlo Ancelotti’s line-up.

Digne has just as much quality as an attacking outlet as he does defensively. He took his assist tally for the season to four in just eight Premier League games by setting up two goals against Fulham last weekend.

A club statement confirmed that the 27-year-old “is due to undergo surgery on Monday before commencing his rehabilitation under the care of the club’s medical staff.”

No timeframe has yet been provided for Digne’s return. As such, it may be that Everton have to call upon their depth to plug the void left in Digne’s absence. Here are the likely candidates for the left-back slot:

The Favourite

One of the rare occasions missed by Digne was against Newcastle earlier in the season in a 2-1 defeat which saw summer signing Niels Nkounkou fill in for the then-suspended Frenchman.

It may well be that Nkounkou is the primary backup option to Digne and could start against Leeds on Saturday, given Ancelotti’s preference to pick the 20-year-old the last time that Digne was unavailable.

The Utility Man

Although a midfielder for most of his career, Fabian Delph has some left-back capabilities. Indeed, it was those capabilities away from his natural position which saw him linking him with a move to Celtic for that very reason.

He is relatively adept in the left-back position and serves as a useful utility option for Ancelotti, proven with his latest appearance against Southampton.

If the experience of Delph is a selling factor, he could get the nod ahead of Nkounkou to start against his former club.

The Wildcard

Thierry Small is being courted by some of Europe’s elite, regarded as one of the most promising left-backs of his generation. He has reportedly been offered a three-year professional deal to stave off interest from rival clubs.

One big statement of faith in the 16-year-old could be a first team promotion, with him making the squad at least to deputise and maybe even to start for the Toffees. A wildcard and an untested talent, it may well be a way to break him into senior football.