The Welshman, who was not risked against Nottingham Forest on Saturday, will have a final check on his fitness ahead of kick-off.
Manager Malky Mackay's options are also likely to be boosted with the return of midfielder Jordan Mutch against his former side.
The 20-year-old has not played for the Bluebirds since the middle of September after suffering a foot injury in training but will have a fitness test before the meeting with a club where he spent half a season on loan two years ago.
The Bluebirds have no new injury worries as they look to set a new club record, no Cardiff side has ever started a season with six consecutive home victories.
Watford are unable to welcome back any of their injured players for the trip.
Skipper John Eustace remains on the sidelines with his long-term back problem and continues to be joined by defenders Piccoli Neuton (ankle) and Nyron Nosworthy (hamstring) as well as midfielders Prince Buaben (hamstring) and Geoffrey Mujangi Bia (groin).
Defender Joel Ekstrand, who has made one substitute appearance this season, is a doubt and will be assessed ahead of the clash in south Wales although he is unlikely to figure in any case.
Manager Gianfranco Zola watched his side snatch a 1-0 win over bottom club Peterborough on Saturday thanks to a 90th-minute penalty from substitute Matej Vydra.
Vydra is one of those competing for a starting berth against the Bluebirds along with the likes of Mark Yeates and Sean Murray.