The two teams previously met in the second-round of this season’s Carabao Cup with the Robins prevailing 3-2 – one of four Premier League scalps they have taken in that competition to date this term.
Watford were in good form when they suffered that loss, but that is not the case heading into Saturday’s tie at Vicarage Road, as they have only won one of their last nine games and are now looking over their shoulder in the Premier League relegation battle.
The Hornets lost to lower-league opposition in the form of Millwall in last season’s FA Cup, although they did win their last FA Cup meeting with Bristol City – emerging as 2-0 victors during a third round replay in 2014.
Boss Marco Silva will be boosted by the return of captain Troy Deeney following a four-match suspension, but Kiko Femenia, Will Hughes, Younes Kaboul, Miguel Britos, Craig Cathcart, Nathaniel Chalobah and Isaac Success all remain on the treatment table.
Bristol City’s heroics in the Carabao Cup are a far cry from their record against top-flight sides in the FA Cup, as they have failed to win any of their last 13 matches against such opposition in the competition.
The Robins are pushing for promotion to the Premier League and have a Carabao Cup semi-final against Manchester City to look forward to, so boss Lee Johnson is expected to make changes to his team with Cauley Woodrow, Matty Taylor and Niclas Eliasson all pushing for starts.
Cardiff remain unhappy with Derby's decision to postpone Sunday's Sky Bet Championship game at Pride Park.
Dundee United boss Csaba Laszlo has been left hoping for St Mirren to slip up in the race to seal promotion to the Ladbrokes Premiership.
Crewe will consider starting Chris Dagnall when they host Forest Green on Tuesday.