The shot-stopper has featured in all of the Blues’ domestic cup encounters this season, and will keep his place between the sticks for the visit to Selhurst Park.
Speaking in his pre-match press conference, in which he revealed Vincent Kompany and Gabriel Jesus may also be ready to start, the manager stated: “We are going to play Willy.”
Asked whether he would rotate the squad further – perhaps with Nolito and some youth players – he replied: “We have seven strikers, it’s a lot. I tried rotation.
“He played at the beginning a lot. I try to involve everyone and it depends what I see against the opponents and in training every day.
“The youth players played yesterday [in the FA Youth Cup] - but in the future hopefully they can play.
“We have followed them from the beginning. There are three, four, five players who have huge talent for that age and I think will be able to play for this club in the future.
“They play good and we are delighted. Brian Marwood and everyone in the Academy have worked for a long time and do really well. They have worked for a long time with the same idea.”
Guardiola also spoke of the importance the FA Cup, and his admiration for a competition he feels is special.
“Of course, we want to go through and win that competition and of course, tomorrow is a final for us,” he continued.
“Winning titles is important. All the clubs want the titles. We need help for the future but I think the club has a plan for the long term.
“The most important thing is we have one idea of how we are going to play and live. Every player will decide how they play.
“They can think about what is best for their team-mate. Every player has their own way of playing. The manager puts their idea on the table and asks them to follow him.”