The winger refused to take the 25th-minute spot kick awarded for a foul on him despite Guardiola's shouts of "Arjen, Arjen" from the sidelines.
On Saturday, Robben had been angered after being told not to take a penalty in the 4-1 Bundesliga win over Mainz with Guardiola instead choosing Thomas Mueller, who was on the bench at the time on Wednesday.
"I do not want to talk about it," a visibly irritated Robben said when asked about the incident. "Let's not talk about it, let's drop it.
"We had a very good game and 5-0 is a great result but we could have done better if we really want to be very critical."
Guardiola confirmed Robben had been his choice for the spot kick but did not comment further.
"I did want Arjen to take the penalty," he said.
It was up to Franck Ribery, who scored from the spot, to smooth over the incident.
"Arjen was a bit irritated," said the Frenchman. "The coach said Arjen but Arjen did not want to shoot.
"That is football. it can happen it's natural," added Ribery.