Speaking after last Saturday's game against Hereford, Warrington manager Mark Beesley admitted that one of his players had got himelf sent off.
The red card happened in the second half after Grivosti reacted to a challendge on him by Hereford's Lewis Hudson.
“The same tackle happened on him two or three minutes before and between them, they didn’t see it,” he said.
“I’ve spoken to Matty and regardless, he then can’t do the same tackle on him.
“If their guy got away with it then maybe he should in his defence, but he shouldn’t be doing that.
“He should try and be more professional about it but he’s got himself sent off, which means he’s going to miss the last game and the first couple of next season.
“It’s affected him and affected us in the game today."