Two sides enduring a torrid run of form meet at Vicarage Road when Watford, who have lost four matches in a row, host an Everton side who have lost three times on the trot.
The Hornets put up very little fight at the Emirates last weekend when Arsenal steamrolled past them, winning 4-0 in the process.
So Flores will be looking for a reaction from his players and they face a team who have been nothing but inconsistent this campaign.
Watford are three points off the magic 40-point mark which would all but guarantee their safety this season. Despite their poor run of form, they would consider this season a mighty success by securing a place in next year’s Premier League, as well as a spot in the semi-finals of the FA Cup.
Roberto Martinez is facing a bit of pressure himself as he has failed to tighten up the Toffees’ leaky defence – they have conceded 42 goals in 30 matches.
With the players that Everton have at their disposal, fans and pundits alike believe the club should at least be in the top half rather than their current position of 12th, a long way from any chance of European qualification.
The FA Cup now looks like being the Merseyside outfit’s only chance of success this season in an otherwise disappointing campaign.
Watford have no fresh injury concerns to worry about this weekend meaning Flores can stick with a similar starting XI that he has used consistently in this campaign.
Valon Behrami is the only doubt for the Hornets after suffering from an illness this week but the midfielder is likely to be in contention.
Meanwhile, the Toffees will monitor the progress of Leon Osman and Steven Pienaar who are both carrying knocks, but Gareth Barry is available again following a two-match suspension.
However, Tyias Browning is still recovering from a knee injury which is set to keep him out until the end of the season.
League Positions: Watford – 14th (37 pts); Everton – 12th (38 pts).
Previous Meetings: Everton 2-2 Watford (August 8, 2015)
Form: Watford – WDLLLL; Everton – WLWLLL
Key Men: Watford – Troy Deeney; Everton – Romelu Lukaku
Shoot Says: Watford 1-1 Everton