Senior has been at Headingley for more than a decade
Leeds Rhinos centre Keith Senior has been fined £1,000 by the Rugby Football League for his post-match outburst at last week's World Club Challenge.
Senior called match referee Richard Silverwood "arrogant" following the Rhinos' 18-10 loss to Melbourne.
Senior had pleaded guilty to the RFL's Operational Rules Tribunal charge of criticising Mr Silverwood's character.
The 33-year-old was fined £500, with a further £500 suspended for the remainder of the season.
The experienced Great Britain international immediately apologised for the remarks, said in the heat of the moment straight after the game at Elland Road on 28 February, in which Mr Silverwood gave a string of controversial decisions which upset the Leeds crowd.
A fine was appropriate, given that this was a personal attack on the referee's character rather than a criticism of a decision by the referee
RFL statement on Keith Senior
In a club statement, several hours after the game, he said: "I would like to apologise for any offence caused by my comments.
"Unfortunately, I let my emotions get the better of me.
"Having had time to reflect on my comments, I appreciate that, like us players, referees have a difficult job to do and we do not have a game without them."
At Wednesday's tribunal, the panel took into consideration not only that public apology but Senior's previous good record during a lengthy career and his admission of guilt.
The RFL said they felt 'a fine was appropriate, given that this was a personal attack on the referee's character rather than a criticism of a decision by the referee.'