Guardiola made eight changes from the team that beat Borussia Dortmund in the Champions League on Wednesday night, as Hakim Ziyech fired Chelsea to a fourth FA Cup final in five years.
Yet Guardiola was not amused by a question in his post match press conference that suggested he picked the wrong line-up against Thomas Tuchel's side and he was quick to snap back.
"Don't say after the game we don't pay attention just because we lose the game," he said. "Say it before. Not after. We respect the FA Cup - we came here to win.
"When you have two-and-a-half days to recover and you play away, and we had to travel longer than three hours, and everyone deserves to play, but don't say we don't pay attention. This team won three finals in a row in the Carabao Cup.
"Say the team played bad, but it's a poor argument. You cannot do what we have done without paying attention. It was a tight game, we were not able to win, so again, congratulations to Chelsea.
"But if you believe we don't pay attention, what would you say if we win with eight changes?"
Guardiola insisted the FA Cup defeat would not derail his side's season, as they look forward to a return to Wembley next weekend in the Carabao Cup final against Tottenham.
"They went through so congratulations," he added. "They made a goal from a counter attack. We didn’t create much in the final third and make many one versus one actions. But in general it was a tight game and anything can happen in these types of game.
"They defended well and are a strong team. I know how we reacted in the second half and it was good. We have not had a midweek free for eight months.
"We have played a lot of games and it will continue. Now it is the Premier League, the Carabao Cup next week. It’s just one more game."
The win was a triumph for Chelsea boss Tuchel, with his side keeping a 13th clean sheet from the 19 matches he has overseen since he succeeded Frank Lampard in January.
"I'm very happy and proud of the team," said the German. "We played against one of the strongest teams in Europe. There’s a big gap between us in the Premier League but the target was to close the gap for 90 minutes here. We played an excellent 35 minutes in the first half and an excellent half an hour in the second half.
"I think we deserved the win. We could have scored the second goal to make it more calm, but we didn’t and had to suffer in the last minutes of the match. We defended with a lot of courage and didn’t allow any big chances. We needed this performance. I’m happy we stole the win.
"There’s a huge gap between us in the league because they’re so, so consistent. To play against each other in one match, anything is possible if you catch the momentum, if you’re brave, free and attack and defend as a team. It’s possible to beat any team for us. Our target was to reach the top level and see what happens, but you need a bit of luck.
"It was a team effort. It starts with the goalkeeper and it was important that the back five and midfielders were close together. It was important we found the rhythm in the first half not to be under too much pressure. That was the key to hurt them and to implement self-confidence.
"We’ve kept on pushing. The mentality and work ethic towards training is fantastic. I couldn’t be happier as a coach to be fighting with this team on the sidelines. It’s a very, very good moment. You see the structure and quality of the players and club. I play my part in this and try to keep the momentum going."