Manchester United head coach Erik ten Hag has revealed that Antony suffered a "serious" injury during Thursday's Premier League clash with Chelsea at Old Trafford.
The Brazil international had to be replaced in the first half of what proved to be a 4-1 victory for the Red Devils after damaging his ankle during a challenge with Trevoh Chalobah.
Antony was stretchered off at Old Trafford and appeared in serious distress, with his availability for the FA Cup final against Manchester City on June 3 now in serious doubt.
The forward, who has scored eight goals during his first season at Man United, will now undergo a series of tests to determine the extent of the damage.
Luke Shaw was also replaced at the interval of the game against Chelsea, with the England international suffering a back injury, although it is believed to be a minor issue.
"It's difficult always to say, straight after the game, but, yeah, Antony is serious. Luke Shaw, we have to see. I don't think it's too bad but we have to wait 24 hours. We'll have a diagnosis and we will know more," Ten Hag told beIN Sports on Wednesday night.
Meanwhile, in a later press conference, the Dutchman told reporters: "It's difficult to say. Let's wait for 24 hours and then we'll know more.
"I don't know [about Antony]. Everyone has seen he came off. I can tell you it is serious but we have to wait a minimum [of] 24 hours, then we know probably more about the status of the injury."
Man United secured a top-four position in the Premier League table courtesy of their 4-1 win over Chelsea, and they will now be looking to keep hold of third on the final matchday of the campaign against Fulham on Sunday.
"It's really important [to finish in the top four]. This club belongs in the Champions League and it's not so easy in the Premier League. It's a tough competition, strong, with a lot of teams competing for that. And we made it, so we make a good season," said Ten Hag after the match.
"I am comfortable here. But I remember after the second game, Brentford, it was tough. But, yeah, I think we construct a team, it's a good spirit. We work very good in the training pitch and we get results.
"We are improving and I think we are in the right direction and we know we are still not there where we want to be, but we are back in the Champions League.
"That was, I think, a really important step. We had to do it because if you want to be successful, you have to be in the Champions League."
Ten Hag has already delivered a trophy in his first season at the club, lifting the EFL Cup at the end of February, and Man United will be looking to make it a domestic double when they tackle Man City in the FA Cup final next weekend.
