The Demons' legal team fronted the league's appeals board on Thursday night in a last-ditch effort to free van Rooyen after the AFL Tribunal had held up the 23-year-old's striking charge on Tuesday night.
Van Rooyen's swinging arm resulted in Port defender Aliir Aliir being concussed, with the Demons forward arguing at the AFL Tribunal that his intention was to mark the ball.
Anais d'Arville, representing van Rooyen on Thursday, argued the AFL Tribunal made an error of law by not allowing an expert biochemist's report to be submitted as evidence.
That expert biochemist stated the time between van Rooyen being aware of Aliir and contact being made was only 0.2 seconds.
That same expert predicted it would have taken van Rooyen between 0.5 to 0.6 seconds to move his arm once noticing Aliir, thus not giving him enough time to avoid contact.
As a secondary argument, d'Arville pointed to rule 18.5.3 that states: "incidental contact in a marking contest will be permitted if the player's sole objective is to contest or spoil a mark".
"My submission is that the words 'will be permitted' mean that if the preconditions of that rule of that law are satisfied, then the conduct cannot amount to a reportable offence," d'Arville said.
He went on to say that if that condition was met, then law 22.2.1, which deals with duty of care, would have no applicationÂ
D'Arville's submissions and the rebuttal by the AFL's legal counsel Nick Pane took more than an hour.
But the three-person appeal board, headed by chair Richard Loveridge, needed just 22 minutes to deliberate before deciding to dismiss Melbourne's appeal.
"We find that the tribunal did not make any error of law," Loveridge said.
The result means van Rooyen's season could be over.
The fifth-placed Demons (15-7) face the ninth-placed Western Bulldogs at the MCG on Saturday in the final round of the home-and-away season.
It means Melbourne will now need to win two finals games for van Rooyen to be a chance of playing again this year.
The 23-year-old is having a breakout season, having kicked 42 goals in 22 games, including bags of six against St Kilda and Richmond.
7°C