Real, Barca make clubs tremble: Pep

Manchester City manager Pep Guardiola says clubs "tremble" when Real Madrid or Barcelona come calling after Raheem Sterling expressed his admiration for Real.

The 25-year-old, who is under contract at the Etihad until 2023, described Real as a "fantastic club" in an interview. The forward was photographed with a City shirt on one shoulder and a Madrid shirt on the other.

City and Real meet in the first leg of their Champions League last-16 tie at the Bernabeu next week, so the timing has raised eyebrows.

Sterling is one of City's key assets and his future could be up in the air if the club fail in their appeal against a two-year ban from European competitions for breaching UEFA's financial fair play rules.

Guardiola said Real and Barca, the club he used to play for and manage, were true giants of the game.

"All the clubs have to know that when Real Madrid or Barcelona knock on the door the other clubs must tremble," he said on Friday. "They will be in a little bit of trouble.

"Barcelona and Real Madrid are maybe the strongest and most powerful teams in terms of their history and how good they are. That is normal and I understand completely."

Guardiola also said he would talk to the City owner about extending his contract, which runs out after next season.