A four-year investigation into Man City's finances have brought about the charges and they could face sanctions ranging from fines, points deduction, demotion and stripping of titles if found guilty.
Guardiola maintains Man City are clean and while defending the club last week, he referenced Gerrard's slip against Chelsea in 2014 that cost Liverpool the title, handing the Citizens the initiative.
Man City won the title that season under Manuel Pellegrini after Demba Ba benefitted from Gerrard's slip to send Chelsea on their way to a 2-0 win.
"I don't know if we are responsible for Steven Gerrard slipping. Was that our fault?" Guardiola said last Friday. "I have respect for Steven – but that moment belongs to us."
But after a period of reflection, Guardiola has admitted his comments did not sit right.
"I apologise to Steven Gerrard for my unnecessary and stupid comments I said the last time about him," he said ahead of Man City's showdown against Arsenal on Wednesday.
"He knows how I admire him and his career, what he has done for this country that I am living and training in. I'm ashamed of myself because he doesn't deserve it.
"I truly believe in my comments in previous press conferences to defend my club, but I didn't represent my club well putting his name in these stupid comments."