Watford's Michael Bryan is struggling with an ankle injury ahead of the game, while his fellow midfielder Piero Mingoia is nursing a thigh injury.
Both men will face late checks ahead of the visit of Sven Goran-Eriksson's men.
Rob Kiernan, Liam Henderson, Eddie Oshodi, Tom Aldred and Josh Walker are all unavailable as they are currently spending time on loan at lower league clubs.
Malky Mackay has no other injury or suspension concerns to contend with as he tries to arrest a worrying slump in form that has gone some way to undoing their fine start to the season, having registered no wins in the last seven games.
And the Hornets are confident the game will go ahead with the Hertfordshire area not being hit as hard by the weather as other areas of the country.
Leicester, meanwhile, look set to be without on-loan goalkeeper Chris Kirkland.
The 29-year-old has suffered a recurrence of his back injury and returned to parent club Wigan last Sunday for treatment, so Chris Weale is likely to keep his place.
Defender Miguel Vitor is fit again after a thigh strain and will be added to the squad.
Bulgarian Aleksandar Tunchev is still missing, but could finally return to full training next week.
Tunchev has been on the sidelines for nearly two years after tearing his cruciate ligament, but has made good progress in his recovery recently.
City climbed to 14th after last weekend's 1-0 win over Nottingham Forest, their fourth victory in six matches.