Watford hope goalkeeper Egil Selvik could be fit to return to the squad for Saturday's game against Wrexham.
The Norwegian has not played since 7 November because of a shoulder problem, with Nathan Baxter making five appearances since then.
"We are working more with Egil. We'll see if it's possible for him to be ready for the next game. He'll be ready soon," head coach Javi Gracia told the club website.
Forwards Kwadwo Baah and Rocco Vata remain sidelined by hamstring injuries - with Baah closer to a first-team comeback.
"The medical staff are doing a great job and making a big effort every single day to help them, so they can recover as soon as possible.