UPDATE: KEPLER Bradley will travel to Melbourne for surgery after scans on Saturday confirmed the Fremante big man's season is over.

A medical report confirmed that Bradley sustained damage to both the anterior cruciate ligament and lateral ligament in his right knee.

He will require a full knee reconstruction.

Bradley's injury struck a sour note in Freo's thrilling one-point victory over Richmond on Friday night.

Bradley hyper-extended his knee attempting a shot at goal halfway through the second term. He collapsed in a heap and had to be helped from the field by two trainers.

Fremantle immediately activated their substitute when they feared the worst for Bradley.

"Kepler has done an ACL. We're pretty confident," Fremantle coach Ross Lyon said post-match.

"He'll have a scan tomorrow, which is really sad for any player. When it's one of your own it makes it worse.

"As you'd imagine, he's not over the moon about it. An ACL in footy isn't ideal, but we'll support Kepler and rehabilitate him.

“But, you know, one door shuts another one opens. Tanner Smith and Jack Hannath will continue. So we'll find a way. That's what we're paid to do."

Nick Suban came on as the substitute, having earned a late reprieve when Paul Duffield failed a fitness test on an injured calf on the morning of the match, but Lyon felt the early substitution tested the fitness of his side.

"When Bradley went down it put us under pressure, like it did the Essendon game for the run.

"Essendon brought on a (Travis) Colyer, and they (Richmond) bring on a (Robin) Nahas. So when you've already spent some tickets it makes it difficult. So we've been on the wrong side of the ledger there."

Lyon was also frustrated at his side's start. After conceding five goals to Hawthorn in the opening term a week ago, Fremantle gave up three to Richmond before they even scored.

"I thought Richmond were super. Their attack on the ball, their spread, they really did pants’ our midfield. We didn't pressure them like we spoke about, so all of the aims, sort of, went out the window.

"But to the players credit they refocused that second quarter. I thought it was an emphatic response.”

Lyon was thankful for the performance of Luke McPharlin, who returned from concussion to blanket Jack Riewoldt, keeping him to just two marks and one goal.

"He’s one of the premier tall defenders in the AFL playing on one of the premier forwards,” Lyon said of McPharlin.

"He was captain tonight and led us brilliantly."

While McPharlin stood strong at one end of the ground, Lyon was frustrated with his forward line.

"Third quarter I thought we had full control and I thought our forwards really slaughtered some really easy opportunities,” he said.

“We had five entries come to nothing. That was really frustrating."

The Dockers head to the Gold Coast next week with three wins and two losses to start the year, which Lyon feels is a fair reflection of their first five rounds.

"We're probably win-loss where we should be, maybe one more. I'm not too sure. Maybe on balance we're where we should be."