Manchester City have submitted a formal complaint to the Premier League alleging that a member of their backroom staff was spat at by a Liverpool fan during the second half of Sunday's 2-2 draw at Anfield.
The club claimed that the incident took place shortly after Phil Foden equalised for City, who added that they have footage of the incident.
Speaking after the game, Pep Guardiola urged Liverpool to investigate the incident and take action. He said: "I didn't see it. I heard about it, the people told me and if this happened I'm pretty sure Liverpool is going to take a measure about this person.
"Liverpool is greater than this behaviour, at every club there are people that make bad actions because of emotion - you have to control yourself. Liverpool is much, much greater than one person so nothing will change (in how) I admire this club, absolutely not.
"The same thing happened a few years ago when they destroyed our bus when we came here. It is certain people, not Liverpool FC. It is always a pleasure to come to this stadium; it’s an honour for this atmosphere, how they support the team."
Guardiola also suggested that referee Paul Tierney shied back from showing James Milner a second yellow card for a foul on Bernardo Silva. "Referees have emotions and he (Tierney) knows when he’s going to see the action he will know it’s a yellow card," he added.
"I understand the pressure, the referee has the pressure, a decision has to be made in one second. It was clear, with 25 minutes left and at that moment it was 1-1. Now I’m more or less satisfied because we drew, but had we lost I would be more angry."