The Reds were hoping to move next Saturday's game from 12:45pm to 7:45pm in order to increase the recovery time for some of their international players.
Fabinho and Alisson Becker will now likely miss the game.
Both players will be on duty with Brazil, who have three World Cup qualifiers over the week.
The last is against Uruguay in the early hours of Friday, October 15, less than 36 hours before the game at Watford.
Fabinho, Alisson, Sadio Mane and Kostas Tsimikas will all go through a 10-day quarantine after featuring for their national teams in red-list countries, however, they will be allowed to train and feature in matches.
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