Watford are four points off the automatic promotion places after winning two on the bounce, including a first away victory since the opening day when they thrashed Sheffield Wednesday 6-2 last time out.
Swansea City ended a run of six games without a win when they beat Oxford 2-1 on Saturday but haven't tasted victory at home since 14 September.
Swansea have won four of their last seven league meetings with Watford (D1 L2), although they failed to win either encounter last season (D1 L1).