The Red Devils were hit by a “small number” of positive Covid-19 lateral flow tests results on Sunday and the clash in west London is at risk of postponement.
One player definitely not expected to be involved is France striker Martial, who continues to struggle with a knee injury.
Martial’s agent also made comments over the weekend about his client seeking a move away from Old Trafford.
But Rangnick said: “If he has a wish to go to another club, it should be the player who informs either the board or myself.
“I don’t communicate with agents via the media and the press. The player hasn’t spoken with me or us about it.
“After the final training session before the Crystal Palace game, after having trained with the team, he informed the doctor and medical staff he would not be available because the pain on his knee is too big, so we have to wait and seewith Anthony.
“To be honest, what his agent says via media is not that much of interest to me.”
United have closed their Carrington training ground for 24 hours due to a number of positive coronavirus tests.
They are in talks with the league over whether it is now safe for them to travel to the Brentford Community Stadium on Tuesday night.
Register for free to continue reading
Registration is a free and easy way to support our truly independent journalism
By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists
Already have an account? sign in
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies