Manchester City manager Pep Guardiola said his players were too physically drained to celebrate their Champions League quarter-final win over Bayern Munich as he aims to learn from past mistakes in Saturday's FA Cup semi-final against Sheffield United.

City remain on course for a treble after seeing off Guardiola's former club 4-1 on aggregate with a 1-1 draw in Munich on Wednesday.

But they face another demanding week with the clash against the Blades at Wembley followed by a potential Premier League title decider against Arsenal at the Etihad on Wednesday.

"I have to see, I have to smell, I have to talk. I have to see how the players feel today," said Guardiola on Friday on whether he will rotate his starting line-up against Championship club Sheffield United.

"After the game in the locker room (against Bayern), they could not even celebrate because of how exhausted they were.

"They were incredibly satisfied. Happy to be in the semi-final of the Champions League for three years in a row. The people sit down, talk a little bit, start to dream, have regeneration drinks, use the phone, hug each other, listen to a bit of music.

"We didn't dance. We didn't take photos. We didn't do anything special.

"We could not have more sequences of passes in Munich that help us rest with the ball. They run a lot."

Only once in Guardiola's seven seasons in charge have City failed to get to the last four of the FA Cup, but they have lost at the semi-final stage in each of the past three years.

"In previous seasons, I rotate a lot and it was not good. I have to think about it. I have many doubts about it," added Guardiola.

"I have to see the training session today. I will see what is their feeling. Of course, they will tell me they want to play. That's for sure. It is difficult to find players who don't want to play.

"But at the same time you have to be sure the players are in the maximum conditions."

Nathan Ake will definitely be missing after the Dutch defender suffered a hamstring injury against Bayern.

Sheffield United will also be without two key players as City loanees Tommy Doyle and James McAtee are not allowed to play against their parent club.

But Guardiola believes that rule in English football should be abolished to match that of European competition.

Joao Cancelo did feature for Bayern in midweek despite joining the German giants on loan from City in January.

"Unfortunately they cannot play. We would've loved that," said Guardiola.

"We loan players to get experience and what better experience would there be than to play a Premier League team in the FA Cup semi-finals for their development? Unfortunately the rule is the rule and they cannot play."