Fremantle defender Luke McPharlin could be set for another stint on the sidelines after injuring his knee in Sunday’s 40-point AFL win over Adelaide.

McPharlin suffered the injury early in the match and is almost certain to miss Saturday’s AFL clash with Richmond at the MCG.

His likely absence is a bitter blow to the Dockers, who were already dealing with news that All-Australian defender Michael Johnson will miss up to a month with a medial ligament strain.

McPharlin missed three games earlier this year due to a thigh injury, and coach Ross Lyon said the veteran’s latest setback was related to an old injury.

“He had a scan. It doesn’t look great,” Lyon told Perth radio station 6PR.

“He hurt it early (in the game). He played out really strongly and did the job on Walker.”

Alex Silvagni is set to replace McPharlin, while rebounding defender Garrick Ibbotson will be shifted into Johnson’s role.

“We’re pretty comfortable with what we can put in with Alex,” Lyon said.

“We normally only play two tall defenders anyway.”

Fremantle could also be without star goalsneak Hayden Ballantyne, who will front the AFL Tribunal on Tuesday night over his high bump on Adelaide’s Matthew Jaensch.

Jaensch was concussed by the heavy hip and shoulder from Ballantyne, but Lyon felt there wasn’t much in the incident.

“I liked how he went about competing and trying to win the ball,” Lyon said.

“I think the overall rule is very confusing and grey.

“I would like to see similar events (viewed) as in the spirit of the game.”

Lyon said Anthony Morabito would be in the mix to make his AFL return against the Tigers, but a final decision won’t be made until later in the week.