Rafael Benitez’ men collected a healthy return of 14 points from nine matches, but have yet to add to that tally due to three defeats in a row.
Three defeats in a row
As a result of the Magpies downturn in form – they sit just five points above the relegation zone.
Failing to win neither of their next two games against the Hornets or West Bromwich Albion will likely see United fall into trouble - with games against Chelsea, Leicester City, Everton and Arsenal all to follow next month.
Benitez will hope to have Mikel Merino fit in time with Isaac Hayden suspended after receiving his fifth yellow of the season at Old Trafford.
Paul Dummett is set to rejoin the Magpies’ matchday squad for the first time since suffering an injury on the opening day of the season.
Jamaal Lascelles and Christian Atsu remain doubts following their respective injuries picked up before last weekend.
For Watford, former Sunderland defender Younes Kaboul is set to face a late fitness test.
While most noticeably, Kiko Femenia and Nathaniel Chalobah are out for the Hornets.
Craig Cathcart and Isaac Success are also sidelined.
Marco Silva has received many plaudits for Watford's start to the season – so much that the Portuguese manager has been strongly linked with the Everton job.
Last week, it was speculated that the Hornets’ 2-0 win over West Ham United could be Silva’s last game in-charge with a move to Goodison Park on the horizon.
However, the 40-year-old remains at Watford for the time being – where he will be looking to continue his fine start – especially away from home.
Watford’s away threat
They have also collected a further point after clawing their way back from two goals down to grab a last-gasp equaliser at West Brom, courtesy of one of this season’s standout performer, Richardlison.
Watford’s two defeat on their travels have come in narrow terms at Chelsea and Everton.
Overall records – The Hornets witnessing the better of recent times
United have lost their last three matches to Watford – all losing by one goal in two league defeats and an FA Cup third round loss.
Before then, Newcastle hadn’t lost to the Hornets on seven occasions after earning five wins and two draws.
In fact, Watford had only beaten Newcastle once in their previous 15 games between 1989 and 2010.
In total, the two sides have met 40 times. The Magpies have won 15 compared to the Hornets’ 12 with 13 of the game ending in a share of the spoils.