Chelsea host the Toffees having failed to win their past three games.
Cucurella said: "It is very important. For me, this is one of the most important games of the season because we played really well before the last two weeks and then we have struggled to win these last two weeks.
"We will be playing at home, we need these three points and we want to stay up there again so I think it is a very important game."
On Everton, Cucurella added: "They are playing really well, they have won a lot of games and they are only having one game a week so they are arriving very fresh.
"Hopefully we can play a good game, we can arrive focused, we can control the game.
"We expect them to be very good in transition and they have really good players so hopefully we can control them and win the game."