Luke McPharlin is expected to miss up to a month of football with a knee injury.

The All Australian defender hurt a medial ligament in his right knee in Sunday’s match against Adelaide but played out the game.

Sports science manager Jason Weber said it was a three to four week injury.

“Luke had a nasty knee injury despite the fact he was able to play the game out,” he said.

“It will run closely to KPI’s.”

Michael Johnson also hurt his knee in the game against the Crows. He sustained a left medial ligament injury.

“Johnson had quite an awkward injury,” Weber said.

“He tried to make a tackle but was slung and, as his foot came to ground, he damaged his medial ligament.

“He will be out for four to six weeks (as) his was quite a solid injury.”

Nat Fyfe went into Sunday’s game under a cloud with an ankle injury, but Weber said the star midfielder pulled up well after the match.

“He put in an extraordinary effort with the physios last week in his treatment,” he said.

“He was exceptional on Monday and will train fully through the week and be available for selection.”

Weber was also pleased with Scott Gumbleton's return to WAFL action with Peel Thunder.

“Scott was fantastic, he did a really good job.,” he said.

“He has been outstanding through the rehab process.

“He fired in the game and we look forward to upgrading him in terms to his game time this week.”