Sterling, in a recent interview, hailed Madrid as a “fantastic club”.
It comes amid City’s two-year European ban from UEFA, with most of their players’ futures now uncertain.
Although Guardiola insisted that he cannot question Sterling’s commitment, he accepted that Madrid and Barcelona are the world’s most powerful clubs.
He told reporters on Friday: “All the clubs have to know that when Real Madrid or Barcelona knock on the door, the other clubs must tremble.
“That they will be a little bit in trouble.
“But, on the same point, you see the commitment from Raheem, every single day when he arrives.
“I don’t know if Madrid or Barcelona call his agent, but I don’t have any doubts about his commitment from the first day to the last day that Raheem and other ones have had – and will have – until the end.”
Affairsofnaija Reports (AON)