Joint record three-time winners Spain face France in Munich on Tuesday after ousting hosts Germany in extra-time.
Explosive new Real Madrid signing Mbappe has struggled at the Euros after breaking his nose in France's first match, scoring once from the penalty spot, but remains Les Bleus' main attacking threat.
"I think football is a collective sport, and it's true that if it was one-on-one it would be tricky, but it's up to us in the end," Cucurella told a news conference Sunday.
"Apart from being good with the ball, we are a very hard-working team, we give everything for each other, and I think that's the key.
"We have to be united, to know what to do in each moment, and above all we need to minimise their counter-attacks which are prehaps their strongest weapons."
Cucurella has been one of the most impressive players in Spain's side this summer, a surprise to some after an inconsistent season with Chelsea.
The left-back had only appeared once for his country before this year, but improving performances at Stamford Bridge in the final months of the season and Valencia defender Jose Gaya's injury helped him claim a starting spot.
With defender Dani Carvajal suspended against France after a red card in extra-time in the 2-1 win over Germany, the 25-year-old could be used at right-back, where he operated for Chelsea on occasion.
"I'll try to give my best, to contribute my grain of sand," said Cucurella.
"I feel more comfortable on the left but in the end I have to try to do the best I can and help the team.
"What's important is that we win, and it doesn't matter who plays, if on Sunday we are in the final."
'These things happen'
The defender was involved in a controversial moment against Germany where the ball struck his hand in the area but the hosts were not awarded a penalty.
"If the referees said it wasn't a penalty, then I will respect that," said Cucurella.
"In the end these are things that happen, they are decisions... (Germany's Toni) Kroos could have been booked before and then sent off.
"Football is a game of errors and accuracies, in the end we were more accurate than them, we scored one goal more and we got through."
Kroos hacked down Barcelona's Pedri in the early stages and the midfielder was substituted and will miss the rest of the tournament with a knee ligament sprain.
The former Real Madrid star wished Pedri a speedy recovery in an open letter to Germany fans after his retirement from football, and the Spaniard replied on Sunday.
"I came to Germany for Euro 2024 and here I will stay, until the end, because don't doubt it, the dream continues," wrote Pedri on social media platform X.
"Thanks Toni Kroos, for your message, this is football and these things happen. Your career and your achievements will always remain."
