Ismaila Sarr and Jeremy Ngakia are doubts for Watford's Sky Bet Championship meeting with Sunderland.
Forward Sarr rolled his ankle in the first half of Tuesday's 2-0 defeat at Blackburn, while defender Ngakia was substituted later in that match due to a hamstring issue.
Left-back Hassane Kamara will be assessed after missing the last two games due to a muscle strain.
Captain Tom Cleverley is closing in on a first-team return following a calf problem but fellow midfielder Imran Louza remains sidelined as he continues his recovery from knee surgery at the end of last season.
Sunderland are likely to be without forward Ellis Simms at Vicarage Road.
The Everton loanee was forced off in the first half of Wednesday evening's 3-0 win at Reading due to a toe injury, with the club waiting to discover the extent of the damage.
Defenders Dan Ballard (foot) and Dennis Cirkin (hamstring) and striker Ross Stewart (thigh) remain sidelined.
Paris St Germain loanee Edouard Michut is still not ready for a debut after suffering a minor injury during his first days of training with the Black Cats.
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