After Wigan beat City 1-0, the DW Stadium was flooded with elated fans. A pitch invasion that saw a frustrated Sergio Aguero lash out at a supporter.
During the tie, Delph's red card sparked an angry confrontation between both benches, with Guardiola and opposite number Paul Cook continuing to exchange views as the sides went in for the interval.
On Wednesday, Jose Mourinho's Manchester United face Sevilla in the last-16 of the Champions League, and the Portuguese didn't shy away from taking a sly dig at his rivals.
Reflecting on United's loss to Bristol City in the Carabao Cup, Mourinho said: "We lost in the quarter-final but we lost like Manchester United likes to lose – with dignity, with fair play, with participation in the happiness of a giant killer."
"So even in the Capital (Carabao) Cup, we lost against a Championship team, I would say that as a Manchester United manager that way of behaving as a big team, even in defeat we were a big team," he added.
In these statements Mourinho appears to imply City did not lose 'with dignity' or 'with fair play' but instead reacted childishly, contrary to how a 'big team' is expected to act.
Wigan and City have since been charged with failing to control their player in the aftermath of Delph's dismissal, while both clubs have been asked to pass on their observations on the crowd trouble after the match to the FA by the start of next week.
Wigan, who ended Guardiola's quadruple hopes, will now face tough opposition in Southampton in the next round of the FA Cup. Fans will be crossing their fingers for another shock defeat to continue their Wembley dream.