The Hornets could move up to the Premier League one season after Blackburn crashed out of the division, but Gianfranco Zola's men can only grab a place in the top flight via the playoff final.
Watford are six points away from Hull City, who sit in second place, while Cardiff City have already secured their promotion to the elite league and are likely to clinch the Championship title.
In contrast, Blackburn, who are currently being led by Gary Bowyer on a caretaker basis, are in danger of getting relegated due to their two-point gap away from the bottom three.
The travelling side may face a tough task, but they can hold onto the fact that they secured a slender 1-0 victory over Watford earlier this season and have won their last two fixtures.
Blackburn Rovers: WWLLD
Possible starting lineups
Watford: Almunia; Doyley, Battocchio, Ekstrand, Briggs; Yeates, Pudil, Chalobah, Anya; Deeney, Vydra
Blackburn Rovers: Sandomierski; Kane, Dann, Givet, Olsson; Lowe, Williamson, Jones; King, Rhodes, Best
Sports Mole says: 2-1