PORT Adelaide's bid to free Junior Rioli from suspension has failed with the AFL Tribunal slapping the dynamic forward with a two-match ban.

But the Power were able to save Rioli from a three-match ban, arguing the 27-year-old's strike on Essendon defender Jordan Ridley was severe instead of high impact.

Rioli collected Essendon defender Jordan Ridley high after sticking out his arm in a clumsy attempt to block for a teammate during Sunday's clash at Adelaide Oval.

A dazed Ridley fell to the ground and was subbed out of the match with concussion in the second quarter.

The 24-year-old will also miss Essendon's game against Brisbane at the Gabba on Saturday night.

After deliberating for 30 minutes, the Tribunal deemed the force of Rioli's strike was high, not severe.

"Rioli's intention was to block Rioli and not strike him (Ridley), he delivered a blow with his hand or arm," AFL Tribunal chairman Jeff Gleeson said.

"On one view he was unfortunate but moving his arm the way he did meant that he was careless to whether he committed a strike."

Port Adelaide's lawyer Paul Ehrlich claimed Rioli did not strike Ridley as he was attempting to shepherd the Bombers backman.

"We say unfortunately because the arm (of Rioli) was up, Mr Ridley ran into it," Ehrlich told the Tribunal.

"The fact there is a concussion doesn't mean the impact was severe."

Ehrlich used many examples during his lengthy argument, saying the contact Rioli made to Ridley was far less impactful than other incidents during recent seasons.

The AFL's counsel Lisa Hannon said Rioli delivered a "blow with some force" while he was running and off the ground.

"It doesn't matter if it was in a blocking motion, there doesn't need to be a swing to be a strike," she told the Tribunal.

Ehrlich even brought up Sydney great Barry Hall's infamous knockout punch on West Coast's Brent Staker 15 years ago when arguing his case.

"There are spectrums of 'severe' impact. At one end of the extreme you'll have – I won't mention his name – in 2008, a certain player (Hall) who hit a certain West Coast player (Staker),"Ehrlich said.

Rioli will miss Port's matches against North Melbourne (away) and Melbourne (home).

The West Coast premiership player has featured in all eight games for the Power this season after his move to Alberton at the end of last year.