Structural mistakes at stoppages cost Fremantle a game it could have won against Greater Western Sydney, ruckman Jon Griffin says.

Freo gave up eight goals from stoppages in the first half against the Giants that contributed heavily to the 18-point loss.

Fremantle coach Ross Lyon laid the blame squarely at the feet of his defenders.

He was pleased with the performance of the rucks, with Griffin having to shoulder most of the load with some part-time assistance from defender Zac Dawson.

Griffin said structural mistakes and costly skill errors hurt Freo in the end.

"It was definitely a game we could have won," Griffin told AFL.com.au post-match.

"They're obviously a great team.

"Structurally we were a little bit inconsistent, which hurt us. In the second half we were a lot better. But you give them eight goals at half-time, it's pretty hard to come back from that.

"That's what is really the frustrating part. There's just a couple of little things that hurt us a little bit. It definitely hurts because you know we're in the game." 

Youth, not winning, the focus for Freo: Lyon

Griffin had a great battle with Giants ruckman Shane Mumford. Griffin had 40 hit-outs to Mumford's 42 and both men had five clearances.

Mumford had 10 hit-outs to advantage in the first half to Griffin's five when the Giants kicked eight goals from stoppages.

Griffin said he loved the challenge of facing Mumford.

"He's a tough competitor. I love the competition and really set myself for a big game. I really enjoy the challenge.

"He's a terrific player and definitely someone I sort of look up to and try to add some of the strengths of his game to mine. It was great battle."

Griffin said the players were seeing signs of improvement despite the 0-7 start to the season, and needed to keep working hard on the track ahead of another huge test against Hawthorn in Launceston next week.