Arsenal's hierarchy reportedly decided to sack Unai Emery on Monday during a meeting held in the United States.
The Spaniard was removed from his position on Friday morning following a winless run of seven games.
However, it has been claimed that last weekend's 2-2 draw at home to Southampton - a game that they should have won easily - served as the final straw for Emery.
According to The Mirror, a meeting was held in the US between head of football Raul Sanllehi, managing director Vinai Venkatesham and Arsenal owner Stan Kroenke less than 48 hours after the Southampton game, during which the decision to pull the trigger was made.
Emery had reported to the club's Colney training ground on Friday for the normal morning session, only to be told by Sanllehi that his services were no longer required.