Erik ten Hag fears Manchester United forward Antony is "unlikely" to recover from injury in time for Saturday's FA Cup final against Manchester City.
Antony was stretchered off during the first half of last week's Premier League win against Chelsea.
United boss Ten Hag had hoped the Brazilian could return to face treble-chasing City in the first all-Manchester FA Cup final.
But Antony has made slow progress this week and looks set to be sidelined at Wembley.
"Unlikely (he will be fit)," Ten Hag told reporters on Friday. "Dos Santos (Antony) still has a chance but it's a really small chance.
"He didn't make the progress, so he still has a chance but unlikely he is available."
Anthony Martial's injury-hit season will also end on the sidelines.
The 27-year-old strained a hamstring towards the end of Sunday's win against Fulham and he will miss the final after scans showed a muscle tear.
Despite the fitness issues plaguing his team, Ten Hag remains confident United have the squad strength to beat arch-rivals City.
"These questions so many times about the absence of players in the last couple of months," he said.
"Every time I say the same answer: it's about the players who are available and many times we were successful.
"We have a good squad and from that good squad we make a good team."
United are looking to complete the domestic cup double for the first time, having lifted the League Cup in February.
Meanwhile, Premier League champions City can become only the second English club after United to win the top-flight title, the FA Cup and the Champions League in one season.
City face Inter Milan in the Champions League final on 10 June.
United fans are desperate for their side to extinguish those dreams as Pep Guardiola's men look to replicate Alex Ferguson's 1999 treble heroes.
"We want to win, we want to win a cup," Ten Hag said. "It's not about stopping them. It is about that we win, that we win the cup. We have a great opportunity.
"That's great that we deserved that opportunity to be in the cup final and then meet Man City. That's a great opportunity.
"We fought so hard for it. I think we progressed that well that we are in that FA Cup final."
City won this season's first Manchester derby 6-3 at the Etihad Stadium, with United coming back to win 2-1 at Old Trafford in January.
United finished 14 points behind City, who won a fifth title in six seasons, and Ten Hag is well aware of the quality posed by the champions.
"They play very good football, so they deserve it. Of course, I look at others because they are opponents and I evaluate it, but we look to ourselves," he said.
"We make very good progress, we are in a good direction and now we use the coming period as well.
"Now we get the opportunity in the summer to make new targets, new goals on the short term.
"But the longer term, yeah, that will stay the same. As I said last year, we want to restore Man United but we have a way to go."