Investigations are underway at the FA following Manchester City striker Sergio Aguero's altercation with a Wigan fan on Monday night.Aguero, who was on the losing side at the DW Stadium as City crashed out of the FA Cup, reacted furiously when a home supporter appeared to spit at him.Footage showed the Argentine shoving the Wigan fan before being restrained by an opposition player and onlookers.According to the Times, Aguero has since told close friends he was spat at following the full-time whistle, hence why he was so angry.Wigan should have done more to prevent the pitch invasion and they've now released a statement saying they are "disappointed" about it all. Chief executive Jonathan Jackson said:"Whilst we appreciate that the vast majority of supporters who ran on to the pitch did so spontaneously to celebrate a famous victory, we were disappointed with the actions of a minority of supporters who acted in an inappropriate manner."Player and staff safety is of paramount importance and we will conduct a full investigation. However, it is important to not let the actions of a few supporters detract from an incredible night at the DW Stadium."A special atmosphere was created by both sets of supporters and the match was yet another memorable day in the history of Wigan Athletic."It's now been revealed that the Wigan fan didn't just spit at Aguero. According to Press Assocation's Andy Hampson, the fan also shouted three words before his vile act: "Suck my d***."Hampson wrote: "Aguero and Man City considering legal action, with the Argentinian understood to have reported he was spat and sworn at by fan on field at Wigan.

"Fan apparently said, "suck my d***," and spat in Aguero's ear."

Disgusting behaviour, I think you'll agree. Aguero's reaction to such abuse was justified and he shouldn't be punished for defending himself - just like anyone else would.

Hampson claims City are also unhappy with the stewarding arrangements at Wigan and feel they didn't prepare adequately for such a big game.