Erik ten Hag says Lisandro Martinez’s knee injury "doesn’t look good" and he is praying the 26-year-old defender has avoided a "personal disaster".

Martinez looked devastated after being forced off on just his fourth appearance since returning from four months out following the reoccurrence of a foot issue. 

He was surrounded by concerned team-mates after going down clutching his right knee having been landed on awkwardly by West Ham full-back Vladimir Coufal. 

Ten Hag is fearing the worst and says "we can only pray" that Martinez, who he signed from former club Ajax in 2022, has avoided serious injury. 

"I can’t say [what the situation is] but it doesn't look good, so there's a big concern.

"But we have to wait for what is the diagnosis and then we can tell you more. 

"Of course we do everything to get the right diagnosis and see what the damage is. 

"He is very sad, very disappointed. We are all. We feel really with him. 

"First of all, it’s a personal disaster when it’s really bad but let’s wait for what it is. 

"But also for the team it's really bad because he definitely brings us a lot."

The Argentina international was able to continue for a short period, only to pull up again and eventually trudge down the touchline to supportive chants from the Old Trafford faithful.

United are well-equipped at centre-back should Martinez remain absent in the long term, with Raphael Varane, Harry Maguire, Jonny Evans and Victor Lindelof all available for selection.