The transfer window opens on June 9 but what do Watford need to do this summer ahead of their Premier League return?
Which positions are Watford targeting?
Sky Sports' Simeon Gholam writes: "The last time Watford were promoted to the Premier League in 2015 they replaced their manager before the start of the season, but Xisco Munoz has the full backing of the club to lead them into the top flight next season, after his arrival last December triggered their incredible run to promotion.
"The Hornets possessed a squad that probably should not have been relegated from the Premier League in the first place, and have lost very little in terms of key personnel. Interest in Ismaila Sarr will be high, but if they could hold onto him ahead of a season in the Championship, they should be able to show enough resilience to keep him again now they have returned to the Premier League.
"Troy Deeney remains the talismanic figure at the club, but his best days are behind him as injuries have taken their toll. Watford's incredible sprint to promotion happened with the 32-year-old on the sidelines from February onwards, and finally finding his long-term replacement will be essential if they are to score enough goals to survive.
"Only Sarr reached double figures in their squad in the Championship last season. Ashley Fletcher is expected to join from Middlesbrough, and former Watford striker Matej Vydra could well fancy a return as he continues to find himself in and out of the side at Burnley - even despite his late-season scoring exploits.
"An emotional return for Ashley Young to his boyhood club is also a possibility and he would add invaluable experience to the side. They may also have a keen eye on Bournemouth's Arnaut Danjuma to give some balance on the left side and add some extra flair and goals.
What do the stats say about Watford?
If a Watford player has the ball in your box, stay on your feet. Nearly one in six of the Hornets' goals came from penalties this season, and across the campaign they found the net 10 times from the spot.
Xisco Munoz's side were rarely free-scoring, despite putting six past Bristol City in February, and created the ninth-fewest chances across the division.
A strong defence underpinned their promotion credentials; they made just 20 passes more in the final third than relegated Rotherham, but without the ball proved a tough nut to crack, winning it back in their own third more times than anyone else in the division.
They topped the billing on clean sheets too, keeping a blank in half of their league games across the season, and conceded the fewest goals of any team by some margin, six fewer than second-best Norwich.
What the club has said
Sporting director Cristiano Giaretta on the club's plans this summer: "We need to strengthen in some positions because even though the squad was amazing, the level is going to radically change. We have a good base for the squad, but we have to add some players in some positions.
"We are not going to change the whole team, but we are going to strengthen some positions with the condition that players we sign for Watford must be better than what we have, otherwise it doesn't make sense."