May has been handed a grade-two charge for his high tackle on Penisini in Penrith's 27-8 qualifying-final win over Parramatta on Friday night.
It means the Panthers rookie will miss Penrith's preliminary final if he takes an early guilty plea and only return for the grand final if the defending premiers make it.
If the 21-year-old fights the charge at the NRL judiciary and loses he will also be out of the grand final the following week.
May was already battling a hamstring injury out of Friday night's win and would have been in doubt for the preliminary final anyway.
His charge comes at the end of a bizarre week for the winger.
He was handed a two-match ban after being found guilty of an October 2020 pub assault last week, but had his suspension deferred until the start of next year.
The league claimed it was the only fair option given the timing of the offence in relation to the guilty verdict.
However it still had several clubs across the league raising their eyebrows, as well as the likes of Issac Luke who missed a grand final through suspension in 2014.
But there will be no reprieve this time unless May fights the charge and wins, with on-field suspensions never deferred until the previous year.
Panthers coach Ivan Cleary argued during the week some would suggest May should never have been suspended at all and did not understand the controversy around the ban being deferred.
But he had no issue with May being sin-binned on Friday night, and also thought it would be a tough ask for him to recover from the hamstring injury in the next fortnight anyway.
"When you've got to come off for a hammy it's not a great sign," Cleary said post-match.Â
"He's had a fair bit on his plate, so that's going to be a hard one to come back from."
Penrith have the option of playing speedster Charlie Staines on the wing, while young gun Sunia Turuva would be another option as an x-factor.
Meanwhile Penrith prop Spencer Leniu is free to play in the preliminary final after only copping a grade-one charge and fine for a high tackle on Isaiah Papali'i.
Parramatta forward Marata Niukore is also able to play in next week's do-or-die semi-final, avoiding a charge after being placed on report for a supposed cannonball tackle.