Watford midfielder Roberto Pereyra had knee surgery in Spain on Tuesday and is set for a spell on the sidelines.
The Hornets will assess forward Stefano Okaka and defender Sebastian Prodl, who are back in training after a hamstring injury and dead leg respectively.
New Crystal Palace boss Sam Allardyce has midfielder Mathieu Flamini available again after a groin injury.
But the Eagles' injury list remains lengthy with the likes of James Tomkins and Bakary Sako amongst the absentees.
MOTD COMMENTATOR'S NOTES
Mark Scott: "Alan Pardew said at the start of the season that in trying to implement a new brand of football, Palace would be "a team in transition and their league position might be affected.