Having calmed down for the post-match presser after a furious finish to the game, Guardiola accepted his fullback deserved to be sent off.
"It's a red card," he said. "It was an unnecessary action and the referee decided what he decided. I'm not here to judge. It can be a red. We have to learn.
"Stay in his position, that's all [I said to the Wigan manager Paul Cook].
"If you want to ask me about football, do so. Nothing happened in the tunnel, nothing happened with my colleague. It was just stay in your position, that's all, and that's finished."
Asked how much disappointment there was that Delph will now be suspended having only recently returned from injury, he said: "A lot. We arrived in an important part of the season and of course without [Benjamin] Mendy and now Fabian for some games. We have to train good, recover and wait for him to come back."