Watford's Jose Holebas has recovered from a back injury and Sebastian Prodl has shaken off illness, so both players are available, but Tom Cleverley (thigh) is still out of action.
Nathaniel Chalobah (knee), Younes Kaboul and Gerard Deulofeu (both ankle) could play before the end of the season but are not yet ready.
Crystal Palace's Jeffrey Schlupp (ankle) has returned to training but the match may come too soon for the defender.
Connor Wickham (groin) is out as are long-term absentees Bakary Sako (ankle), Jason Puncheon and Scott Dann (both knee).
Did you know?
Watford are winless in their last six home meetings with Crystal Palace in all competitions (D3 L3), since a 2-0 victory in the Championship in February 2009.
This will be the only Premier League match played on Saturday at 3pm BST. The last time that happened was on 7 March, 2015, when Tottenham Hotspur won 2-1 at Queens Park Rangers.
Watford have lost four PL matches this season by goals conceded in the 90th minute or later, including their last match against Huddersfield Town. This is the most by a team in a single season in the competition’s history.
Wilfried Zaha has scored in consecutive PL appearances and is aiming to score in three in a row for the first time.
Club previews
Watford: Gracia: It's vital for us
Crystal Palace: Wan-Bissaka signs extended deal
Referee: Chris Kavanagh
Assistants: Lee Betts, Peter Kirkup
Fourth official: Graham Scott
