Manchester United manager Erik ten Hag has revealed that Antony will miss Wednesday's Premier League meeting with Leeds United through injury.
The Red Devils are already without the services of long-term absentees Christian Eriksen and Donny van de Beek due to ankle and knee injuries respectively.
Casemiro will serve the first game of a three-match suspension after he was shown a straight red card in Saturday's 2-1 win over Crystal Palace following an altercation with Will Hughes.
Speaking ahead of Wednesday's home game against Leeds, Ten Hag stated that United will not appeal Casemiro's red card.
Ten Hag told reporters: "Consider, yeah, still it's for me, not the right decision, but I don't think we have a chance in a legal process."
The Brazilian is set to miss the two games against Leeds United - which will take place over the next five days - and a home meeting with Leicester City.
Casemiro's absence could result in January signing Marcel Sabitzer being rewarded with his first start for United.
The Dutchman also confirmed that Anthony Martial and Scott McTominay remained sidelined and that Antony will also miss out
The United boss said: "They [Martial and McTominay] are not involved tomorrow, and the same with Antony, also not available tomorrow, so we have to sort it out."
Antony appeared to pick up the injury from a challenge from Crystal Palace's Jeffrey Schlupp in the second half of Saturday's victory.
With Antony ruled out, Jadon Sancho is in contention for his first starting place since October 22.
The former Borussia Dortmund winger has spent time away from the first team to work individually on his physical and mental state.
However, he returned to action in the second leg of United's EFL Cup semi-final against Nottingham Forest, featuring for the final 28 minutes.
United currently sit in third place in the Premier League table, and they will move level on points with rivals Manchester City if they win on Wednesday.