Wakefield coach Chris Chester has said he is "disappointed to be associated" with fans who have abused full-back Scott Grix online.
The 33-year-old made a late error to give St Helens victory at Belle Vue last week.
The defeat could potentially be damaging to Trinity's hopes of finishing in the play-off places.
Chester said Grix had "copped some ridiculous stick... from his own fans from behind the keyboard".
He added: "I'm very disappointed to be associated with those Wakefield fans. Some of it has been just disgusting which I wouldn't expect from any fan, never mind our own.
"He's probably been our best player this year and he didn't deserve the abuse and criticism that he got. First and foremost Grixy is a very good rugby league player and off the field he's a very good person as well."
Defeat by the Saints means Wakefield must win at Hull FC on Thursday to put their top four hopes back into their own hands going into the final game of the season.
Former Hull KR coach Chester has backed Grix to recover from the mistake.
"It's been put to bed now. Grixy will play this week," Chester said.
"He's regularly been in the top two or three players every single week this year and he'll want to make amends for last week. He's trained very well this week and he's a very important player for this team moving forward."