FREMANTLE ruckman Aaron Sandilands has accepted a one-match ban for rough conduct, ruling him out of the Dockers' season opener against the Western Bulldogs.

However, the Dockers will raise their concerns with the AFL about players going third man up in the ruck.  

In the first Match Review Panel sitting of the season, Sandilands was charged for his high bump on Richmond's Ben Griffiths in Friday night's NAB Challenge clash in Mandurah.   

The Dockers were granted an extension to consider their options on Tuesday but decided not to contest the charge and risk an extra week on the sidelines. 

Fremantle football manager Chris Bond said that ultimately it was a risk the club wasn't willing to take. 

"After seeking advice from our legal team on the Match Review Panel’s decision it became apparent that any challenge was a high-risk strategy that would more than likely see Aaron suspended for two weeks as opposed to one after an early plea.
"Having said that, we also believe there are currently a number of grey areas in the rule that saw Aaron charged with rough conduct, which we will be seeking clarification on from the AFL.
"We also have concerns about the third-man up situation which we also plan to raise with the AFL."

Despite the offence occurring in the pre-season competition, Sandilands must serve the penalty in the regular season after his bump was classified careless conduct with medium impact to the head. 

Click here to read the full MRP statement

Fremantle could have decided to challenge the medium impact grading, with a charge of low impact bringing the penalty down to a financial sanction only. 

Sandilands made high contact to Griffiths' head during a ruck duel in the third quarter of the clash.

He moved to his left to block Griffiths' run, with the Tigers using a third man up in the contest.

Griffiths was concussed and didn't return to the ground. He will be assessed by the Tigers this week before Saturday’s clash against Hawthorn.  

The original penalty was two matches, but Sandilands has no applicable record, giving him a one-match discount.

Even though Sandilands pleaded guilty, he will still be eligible for this year's Brownlow Medal.

A medical report from the Tigers, which confirmed Griffiths suffered concussion, was used in settling the final penalty.

There were no other incidents assessed from the first round of NAB Challenge matches.