"I won't go into whether Michael was right or wrong in saying what he did because it is now past but I will say one thing, whoever is advising him on what to say and more importantly on the ramifications on what he says needs a good kick up the backside," Ella wrote for sportsta.me website.
"I know Michael well and sometimes you need to get in his face and tell him the facts whether he wants to hear them or not, because I think (Bill) Pulver and the ARU board certainly don't have the balls to do it."
Ella said Cheika has been "seething on a daily basis" over the June series loss to England.
The Wallabies would love to silence the critics by beating England and winning a Grand Slam, continued Ella, but the former Australian assistant coach queried Cheika's habit of picking players out of position, which he has done again with David Pocock starting at blindside flanker against Wales.
"Having a solid squad is great but as we have seen all year, it's where he puts these players that is anyone's guess," Ella wrote.
"At least Michael has been consistent is playing players out of their normal positions so he will either live or die by these selections.
"I think Michael is now skating on thin ice because as the old saying goes, you are only as good as your last game.
"No one will care if he has won a Heineken Cup or a Super title if he doesn't win at least more than 50 per cent of the games in the north."
