Jonny Evans
Evans went off after 30 minutes at the King Power Stadium.Sky Sports/Twitter

Manchester United will learn the extent of Jonny Evans' ankle injury following a scan on Monday after the Northern Irishman left Leicester City's King Power Stadium on crutches.

Evans was replaced by Chris Smalling after 30 minutes in United's 5-3 defeat to the Foxes and was later spotted wearing a protective boot on his right foot, with the club later confirming the player had suffered an ankle injury.

United boss Louis van Gaal confirmed that the full damage sustained by Evans will be revealed on Monday when the player undergoes a scan which could result in the 26-year-old being ruled out for a significant period of the season.

"I don't know how bad Evans is," Van Gaal said. "We have to wait for a scan tomorrow but he is on crutches."

Injury to Evans was overshadowed by a torrid United defensive display which saw them relinquish a 3-1 lead and concede four goals in 21 minutes of the second half, run ragged by Nigel Pearson's newly-promoted side.

Jonny Evans
The Northern Ireland was later spotted with his right food in a protective boot.Sky Sports/Twitter

The performance once again exposed United's policy in the transfer window in which they failed to sign a recognised centre-back to replace Nemanja Vidic and Rio Ferdinand, and Van Gaal faces a selection dilemma for the visit of West Ham United next weekend.

Tyler Blackett's red card for fouling Jamie Vardy in the box will see him miss next week's game, which added to the expected absence of Evans, again leaves United short of options.

Marcos Rojo is likely to partner Chris Smalling in the centre of the United defence while summer signing Luke Shaw, who is yet to make an appearance for his new club since joining from Southampton, is also in contention to feature

Shaw's fitness was heavily scrutinised by Van Gaal following the World Cup before a hamstring injury ruled the England international out of the start of the season.

But Van Gaal told MUTV: "I think that Shaw shall be fit enough to play [against West Ham]. Rojo can play and Smalling can play, so we can manage. But it's a thin choice."