City were forced into a 28th minute change following the right-back's collision with Jack Grealish, which required attention from the physio and left him limping until he was substituted for Oleksandr Zinchenko.
Guardiola admitted he is yet to speak to his medical team, but is hopeful Walker’s problem will not keep him out long term.
“I haven’t spoken to the doctor,” the City boss said at his post-match press conference.
“If Kyle asks to be out, it is because something happened. Hopefully it is just a kick.
“Kevin put his hand on his leg, so I have the feeling it will be something muscular.
“It is normal, these things happen with this amount of games.”