The double Lions tourist was sent off in Munster's crushing defeat to Leinster on Friday and could now miss the opening two rounds of Heineken Cup action and the November internationals.
Hayes, who was called up as a late replacement on this summer's tour of South Africa having also travelled to New Zealand four years ago, was red carded for an alleged use of the boot on the head of an opponent.
The 35-year-old was involved in a 55th-minute incident with fellow front rower Cian Healy and could now face a lengthy suspension.
With the mid-range ban for such an offence starting at five weeks, Hayes could well be forced out of Ireland's autumn clash with Australia on November 14.
A lengthier ban may see him miss the games against Fiji and South Africa on the following weekends, while even a lower end suspension of a fortnight would still see him miss Munster's European openers against Northampton and Treviso.
A disciplinary hearing into Hayes' sending off will be heard by Irish Rugby Union officials as Magners League rules state that a player's home union acts as the investigating force.
Capped 94 times by his country, Hayes has an impressive disciplinary record since making his Munster bow in 1998 - something that could to be taken into account when it comes to sentencing if he is found guilty of the charge.