STAR Brisbane Lions midfielder Simon Black says his side lacks the maturity needed to produce consistent four-quarter efforts.

Through much of the season, the Lions have shown encouraging signs but have been unable to sustain their performances throughout entire games, which was again on show in their 23-point loss to Fremantle at Patersons Stadium on Saturday night.

Defeat to Fremantle was the 15th-placed Lions fourth consecutive loss and left them with just two wins from 13 games this season.

Black said he was frustrated that the young side again faded out in the last quarter, in which they were kept scoreless, which was similar to their loss to Richmond the week before.

"We were pretty good for three quarters (against Fremantle), but for us to be a decent side, we have to sustain our efforts for longer periods," he said.

"It's been happening all year, it's a maturity and development thing that we're going through and we're just not there yet.

"We've got to look at ourselves individually. It's like a title fight in boxing, you've got to be able to sustain that effort in the later rounds and that's where we're getting beaten up.

"Hopefully (we're on the right track), we're making in-roads. But we're still not close enough. It's going to take a while.

"Late in the game we didn't give enough as a group. Our pressure dropped off and Fremantle were able to get on top and it's very frustrating."

The 2002 Brownlow Medallist said it was important that he and the Lions' other experienced players, such as Jonathan Brown and Luke Power, helped the younger brigade develop physically and mentally.

"I've just got to keep being around a while and reinforcing what it takes to be a better player individually, which will help collectively as a team," he said.

"It's an ongoing process. But hopefully I can stay around long enough to see us fire back up the ladder again."

Black was the Lions' best performer against Freo, finishing with 19 kicks, 14 handballs and seven tackles as he led by example.

The 32-year-old played his junior football with East Fremantle and has always enjoyed prolific performances against the two sides from his home state.

"I love coming back to Western Australia and playing at Subi," Black said.

"I've obviously got fond memories from WA growing up, being a WA boy, so it's always good to play here. It's a big ground and I enjoy it."

Black wasn't the only WA product to perform well, with Matthew Leuenberger (25 hit-outs), Daniel Rich (11 kicks, five marks and two goals) and Rohan Bewick (10 kicks and seven marks) all solid contributors.