In his pre-match press conference on Tuesday, Mourinho had referred to Guardiola's response to the officials' decision to disallow Pedro's effort during the Copa del Rey final, claiming he had created a new category of coach by complaining about correct decisions.
"Up until now we've had two groups of coaches," Mourinho said. "[There's] a very small group who didn't talk about referees. Then there's a larger group, of which I'm included, of coaches that criticises referees when they make big mistakes.
"And with Pep's statements we've come to a third group, which is a one-person group, who criticises good decisions made by the referee. I've never seen this before."
Guardiola, at his press conference later in the day, issued a strong response.
"Tomorrow at 8.45, we will meet each other on the pitch," Guardiola said. "Off the pitch he has already won.
"In this room [press room], he's the f*****g chief, the f*****g man, the person who knows everything about the world and I don't want to compete with him at all. It's a type of game I'm not going to play because I don't know how.
"I won't justify my words. I congratulated Madrid for the cup that they won deservedly on the pitch and against a team that I represent and of which I feel very proud.
"Off the pitch, he has already won, as he has done all year. On the pitch, we'll see what happens."
He added: "If you think that his allegation that I always complain about the referees is true after you've all heard from me over the last three years, well, there's nothing I can do. Off the pitch, there's nothing we can do to fight that."
Guardiola does not believe the war of words between the coaches will have any influence on the players.
"Do you think the players will run more because I've spoken to Jose through the cameras? It's the Champions League semi-finals," he said. "The players won't be motivated by this - they know what I think about everything associated with this game."