Pep Guardiola has said Manchester City cannot compete with Real Madrid's history in the Champions League but has challenged his players to prove that the Spanish giants' 13 titles mean nothing when the two teams meet in the competition's semifinal on Tuesday.

City are aiming to become champions of Europe for the first time and meet Real Madrid, the competition's most successful team, for a place in the final in Paris in May.

- Stream ESPN FC Daily on ESPN+ (U.S. only)

Guardiola insisted that City, who are playing in the last four for just the third time compared to Real Madrid's 31, cannot compete with their track record but said that won't matter when the first leg kicks off at the Etihad Stadium.

"They have been here many times," Guardiola said at a news conference on Monday.

"The history is there and we cannot change it but it's 11 vs. 11. The players will decide. We are playing a team who have been here many times, that is why they have this -- and we don't.

"We can't imagine what is going to happen but it is 11 vs. 11. Move players, how strong they are mentally, that will make the difference. Carlo [Ancelotti] and myself won't win it. Players are the reason why."

Guardiola has selection problems ahead of the first leg with doubts over who will play at fullback. Joao Cancelo is suspended while Kyle Walker and John Stones are both carrying injuries and will be assessed on Tuesday morning.

"They are doubts," added Guardiola. "John has not trained since Brighton and Kyle has not trained for the last week. We will see how they feel and I'll speak with them and take a decision."

Meanwhile, Raheem Sterling has refused to be drawn on his City future as he prepares to enter the final year of his contract at the Etihad.

The England winger has a deal until 2023 and has been linked with a move to Real Madrid.

"At the minute I'm just happy to be playing, happy to be contributing with the team," Sterling said.

"I think that is the most important thing. At this period, I think it would be selfish of me to speak of any contract situation and I'm just happy to be playing football and see where we are at the end of the season."