Walter Mazzarri's men recorded their first domestic win in almost two months, as Miguel Britos notched his first goal for the Hornets in a narrow 1-0 win over basement dwellers Sunderland on Saturday.
The Uruguayan's header on the hour mark this past weekend saw the Hertfordshire side move seven points clear of the drop zone, into 12th spot in the league standings.
The Baggies growing resolute back line frustrated Jose Mourinho's men to the point the Red Devils' boss was involved is a spiky post-match interview with a TV reporter.
Tony Pulis' men have now taken four points from games against the so called 'bigger clubs' following on from their surprise victory over struggling Arsenal before the international break.
Successive wins for Mazzarri?
West Brom have lost just six times on the road this term, but only twice at Tottenham Hotspur and Everton since the turn of the year.
For the Hornets, their Jekyl and Hyde campaign continues a-pace, with victory over the Black Cats their first win since early February in back-to-back wins away to the Gunners and home to Burnley.
Mazzarri's men have failed to win successive games at home this term, as the threat of relegation still lingers in the shadows.
Tuesday's meeting will be the fourth time the duo have met in the Premier League, with both having one in a piece to their name. When they met last season at Vicarage Road, the two sides shared the spoils in a drab goalless draw.
Watford are set to be without both Younes Kaboul and Valon Behrami respectively with hamstring injuries.
Christian Kabasele and Ben Watson are also ruled out, with midfielders Roberto Pereyra and Mauro Zárate ruled out until next season.
Baggies boss Tony Pulis says he will wait on the fitness of 'one of two unnamed players' for the trip to Hertfordshire.
Winger Matt Phillips could make his first start since February, after injury but will be assessed late on.