Troy Deeney is expected to return to Watford's squad after missing the win against Cardiff with an ankle injury.Piero Mingoia is fit again after a thigh injury and could be among the substitutes, but Michael Bryan's ankle problem keeps him sidelined.
Portsmouth midfielders Michael Brown and Richard Hughes will not be selected because of ongoing contract issues.
Dave Kitson is suspended, while fellow striker Danny Webber (knee) will miss the game against his former club.
MATCH PREVIEW
Watford's 4-1 victory against second-placed Cardiff last time out was their third consecutive win, left them a point away from the play-off spots, and most important of all underlined the fact that they do not and need not fear anyone.
The Hornets, unbeaten in four home matches, have netted a whopping 42 goals this season and their thrashing of Cardiff came soon after their 3-1 triumph at leaders Queens Park Rangers. Not bad for a side widely tipped to struggle this season.
Portsmouth are 13th and their season so far has been marred by inconsistency and ongoing financial issues. But they too have reason to believe that they are a match for any team in the Championship - particularly away from home.
Pompey are unbeaten in four matches and have drawn their last two. They have won on the road four times this term - and three of those victories have been against sides currently in the top half of the table.
MATCH FACTS
Head-to-head
• Portsmouth have won 20 and Watford 16 of the 48 previous matches between these clubs.
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• Pompey's only win in 10 league visits to Vicarage Road over 20 years was a 2-1 victory in April 1996.
Watford
• Watford have drawn two and won three of their last five league games.
• Their 42 goals in 22 Championship games is an average of 1.91 goals per game - the best ratio in the division.
• The Hornets have lost their first match of the calendar year in both of the last two seasons.
• John Eustace is in line for his 100th appearance for Watford, and keeper Scott Loach his 100th league appearance for the club.
Portsmouth
• A draw for Portsmouth would see them draw three matches in a row for the first time in eight years.
• They have not lost their first match of a calendar year since 2006.
• Like Watford, Pompey are yet to lose a Championship match this season after conceding the opening goal.
• Striker Dave Nugent is hoping to make his 200th league start.
Source: BBC Sport
Source: BBC Sport