Andrew Ackerman's brother James died while playing rugby league as the result of a shoulder charge three years ago.
Now, he's urged NRL chief executive Todd Greenberg to take action against Melbourne fullback Billy Slater for a similar challenge.
NRL fans wait to find out if Storm star Billy Slater will be suspended for a shoulder chrage against Cronulla Sharks winger Sosaia Feki in the 14th minute of the preliminary final at the weekend.
Slater was charged with a grade-one infringement. If found guilty by a judiciary panel on Tuesday evening, he will miss Sunday's grand final.
While many have voiced their support for Slater, Ackerman took to social media to share his concern over the incident.
"Once again, when the shoulder charge comes into play this bloke right here (he pointed to a picture of James) is mentioned," Ackerman said.
"Now he is dead as the result of a shoulder charge. I watched him die that day, it's not something I thought I'd ever have to watch.
"Now Billy Slater should be found guilty of a shoulder charge. I know there was no malice nor intent to hurt in this tackle. No one was injured. But a shoulder charge was used."
Addressing Slater, Ackerman said: "Why couldn't you wrap your arms around the bloke?
"You know the rules. Play by the rules. You are a great player, Billy, no one is denying that.
"You have won premierships. You have won Origins … You have done it all.
"If you happen to miss your grand final come next week because of a shoulder charge so be it."
Slater, who has played 13 seasons in the NRL - all for the Storm - announced his retirement earlier this year, and Sunday's grand final would be the last match of his career.