Alcaraz is one win away from a second successive Wimbledon title following his 6-7(1), 6-3, 6-4, 6-4 victory against fifth seed Daniil Medvedev in Friday's semi-final.
But he risked the wrath of the crowd at the All England Club with a cheeky comment about a potential super-Sunday for Spain during his on-court interview after dispatching Medvedev.
"It will be a good day for Spanish people as well," defending champion - and Real Madrid fan - Alcaraz said when asked to look ahead to the weekend.
That triggered light-hearted boos from fans before Alcaraz countered with a smile: "I didn't say Spain is going to win but I say it will be a fun, fun day."