Already without Waerea-Hargreaves for Friday night's do-or-die clash with South Sydney, Robinson confirmed on Thursday the Roosters had suffered another blow with Joey Manu ruled out with a hamstring injury.
Corey Allan will come into the Roosters' team and face his old club, while James Tedesco is confirmed to return from concussion at fullback.
But it is Waerea-Hargreaves' situation that has frustrated the Roosters most, after his moment of madness against Wests Tigers last week when the Tricolours already had the game won.
Waerea-Hargreaves copped seven games in bans for a late and high hit on Apisai Koroisau and subsequent headbutt of Stefano Utoikamanu when a melee ensued.
The suspension means the Roosters are without their most experienced player for the blockbuster final-round clash against the Rabbitohs, with both sides needing to win to keep their season alive.
There is also every chance the ban could linger deep into next year, depending on how far the Roosters play into this season's finals and if end-of-year representative fixtures count to it.
Robinson has been a staunch defender of Waerea-Hargreaves over the years, regularly claiming he is more scrutinised than other players.
But in this case, Robinson said he was simply left angry by the big Kiwi.
"Yep I am. I think it's only natural to be that way," Robinson said.
"That doesn't change the way that I think about him or the care that I have for him.
"But of course, you're angry because you represent the club and we're all fighting for something. And for him not to be there to be a part of that is is disappointing."
Robinson said he had given his disappointed forward space this week, but suggested the time would come for a serious sit down with the 34-year-old.
And he is adamant it must be a turning point for the prop, who has been charged six times across the NRL and international rugby league in the past 12 months.
"It's seven weeks, so you'd like to think (it's a line-in-the-sand moment)," Robinson said.
"That was unnecessary. Last weekend, it didn't need to happen in the context of the game.
"His intimidation is an important part of the game, and people enjoy watching that, but that didn't feel like it was one of those moments.
"Seven weeks is a quarter of a season. It's a long time."
Playing the best football they have all year, the Roosters will need to beat Souths and then hope either North Queensland or Canberra lose in order to make the finals.
If the Roosters do qualify, Robinson said he expected to have Manu back for their elimination final.
"He's pretty good. He ran the AlterG the other day," Robinson said.
