LISANDRO MARTINEZ was spotted with his foot bandaged after coming off against Wolves.
After being withdrawn by Erik ten Hag, he was spotted receiving treatment in the away dugout.
Eagle-eyed fans saw a member of the United medical team bandaging up Martinez’s left foot.
The potential injury is a concern following his recent return to action.
Martinez had been sidelined since September with a foot injury before returning two matches ago against Tottenham.
His injury woes have limited the World Cup winner to just nine appearances so far this season.
The Red Devils are already without fellow defenders Tyrell Malacia and Victor Lindelof, who are stepping up their comebacks on the training ground.
Meanwhile, Anthony Martial, Mason Mount and Aaron Wan-Bissaka also remain sidelined.
Reacting to Martinez’s potential setback on social media, one fan wrote: “This doesn’t look good.”
Another supporter simply commented a crying emoji in response.
Martinez’s return had been highlighted as a potential turning point for United’s season under Erik ten Hag.
Supporters praised his dominant display in the recent draw with Tottenham, his first appearance since coming back from injury.
Since signing from Ajax last summer, the 26-year-old has made 53 appearances for United, scoring once.