City head into the first major domestic final of the season with Guardiola sticking to his established policy of using Trafford in cup competitions, despite the England Under-21 international largely playing second fiddle since the arrival of Gianluigi Donnarumma. The 23-year-old, who returned to the Etihad from Burnley in a 27 million pound move at the beginning of the season, had initially been tipped as Ederson's long-term successor but has found opportunities limited.
Guardiola nevertheless confirmed Trafford would start, framing the decision as one made with the team's broader objectives in mind rather than the individual. "Yes," he said when asked if Trafford would be in goal. "For the team it's a big moment."
Trafford has impressed when called upon, keeping five clean sheets and conceding just 10 goals in 12 appearances this season, including a standout display in the semi-final victory over Newcastle. His performances have come amid public comments earlier this year expressing surprise at his lack of regular minutes, but Guardiola offered little reaction to those remarks.
"Players can be happy, unhappy. It is what it is," he said. "They have to be here to do the best they can do and after we will see what happens at the end of the season. The important thing is they have to be ready."
While praising Trafford's attitude as "good" and stating he was "beyond happy" with his professionalism, Guardiola stopped short of guaranteeing the goalkeeper's long-term future at the club, leaving open the possibility of movement when the campaign concludes.
The final arrives against the backdrop of an intriguing Premier League title race. Arsenal currently lead City by nine points, albeit having played a game more, with another meeting between the sides scheduled at the Etihad Stadium next month.
However, Guardiola dismissed suggestions that victory at Wembley could significantly influence the title battle. "I don't know," he said. "Of course winning helps, but we can win on Sunday and then be bad in the league and go the opposite direction.
"I've learned that with many competitions and many games in a short time, you have to have the ability to forget and move forward, in good and bad moments. Learn what you have to do better."