Milner struggled to deal with Phil Foden throughout the 2-2 draw at Anfield and was cautioned in the first half for pushing the City winger back.
With a score of 1-1 in the second half, Milner knocked Bernardo Silva down near the halfway line but escaped a second yellow card. A few minutes later, Mohamed Salah scored to put Liverpool back in the lead.
Bernardo and Guardiola both received a yellow card from Paul Tierney for their complaints about the incident, but Kevin De Bruyne scored an equalizer in front of the Kop to ensure the game ended level.
Guardiola told Sky Sports after the match that Milner should have been sent off and, after performing his post-match media duties, ran into the former City player at the mouth of the Anfield tunnel, the two sharing a warm embrace before having a conversation.
When asked what the two had discussed, Guardiola first joked that it was golf before adding that the controversial incident had occurred.
« [We were talking about] our swing is a better golfer than I am and he gave me some golf tips, ”he said.
“He’s a nice boy, we couldn’t be together in Manchester, but I know from the back room staff how nice he is. We talked a bit about the game and the yellow card. He was joking. “
Of the incident with Milner, Guardiola said: “I understand the pressure. The decision must be made in a second. Maybe yes maybe no…
“We could have lost for that reaction and I would be more angry. Arbitrator [when he sees it back] knows full well it’s a yellow card. “