Sarri is happy to see Chelsea ride their luck
Chelsea 3 Watford 0
Maurizio Sarri recognised Chelsea had been "lucky" to secure a vital victory over Watford after finding themselves "in trouble" during the first half.
The Blues have secured qualification for next season's Champions League after moving up to third in the Premier League with a 3-0 home win that followed Tottenham's 1-0 defeat at Bournemouth.
Arsenal's failure to get the better of Brighton means Sarri's side will return to European football's top table following a difficult season in which the Italian has been heavily criticised and the top four has often appeared beyond their reach.
Chelsea struggled for intensity until taking the lead through Ruben Loftus-Cheek early in the second half, perhaps because of Thursday's Europa League semi-final first leg at Eintracht Frankfurt, and Sarri said: "We were in trouble because we were tired, physically and mentally.
"Then, in the second half, (Watford) lowered their intensity so we were in control. We were lucky, of course, because we scored after two minutes. After the first goal, probably we improved mentally and were able to play very well for 30-35 minutes.
"In the first half we were tired and in trouble, tired mentally. But it's not easy to play (again) after 60 hours."
One concern for Sarri is N'Golo Kante's fitness. The energetic midfielder was substituted and replaced by Loftus-Cheek after suffering a hamstring injury, making him a doubt for a crucial week in which they host Frankfurt in the second leg of their last-four clash.
Discussing Kante's condition, Sarri said: "The problem is with his hamstring. But I made a mistake because, probably, he had to rest. Sometimes it's very difficult to put on the bench a player so important like (Eden) Hazard, like Kante, but you have to do it.
"We have to wait until the morning (to determine the severity of the injury), but it's very difficult to recover him for the next two matches."
After Loftus-Cheek's header, a further header from David Luiz and then Gonzalo Higuain's close-range finish increased the hosts' lead, leaving Watford 10th.
Their manager Javi Gracia recognised they may have been distracted by the prospect of their FA Cup final against Manchester City later this month, saying: "We have to play the final. It's normal for it to be on our minds, but we were focused on this game (against Chelsea).
"We have to finish the league next week, and then have an important final. If your behaviour always is defending badly at corners and free-kicks, I'd be worried. But it's not like that. I'd prefer to be optimistic."
CHELSEA: Arrizabalaga, Azpilicueta, Christensen, Luiz (Cahill, 89 mins), Alonso, Kante (Loftus-Cheek, 10 mins), Jorginho, Kovacic, Pedro, Higuain (Giroud, 79 mins), Hazard. Unused subs: Barkley, Caballero, Zappacosta, Willian.
Watford: Foster, Femenia, Mariappa, Cathcart, Holebas, Chalobah (Cleverley, 67 mins), Doucoure, Hughes, Pereyra, Deulofeu (Success, 83 mins), Deeney (Gray, 83 mins).
Unused subs: Gomes, Janmaat, Masina, Kabasele.
Referee: Paul Tierney (Lancashire)
Man of the match: Ruben Loftus-Cheek
Match rating: 7/10.