After their eighth loss, the German manager said too many of his players are not 100 per cent fit to keep up pressure on the pitch, despite being halfway through the A-League season.

"Getting fitter is a big problem that we have. Too many players are not 100 per cent fit and that's the reason why we can't put the pressure on all the time over 90 minutes on a high level," Babbel said.

"But we knew it before so we have to work with these guys to make them better, fitness wise.

"You do this and you don't do the easy mistakes, they're killing us at the moment."

Babbel, who appears to be the third A-League coach on the chopping block this season, grappled to find a reason why his players are not fit enough after 14 games.

"They're different stories. Some players haven't played a lot in the past and a game is different to training and also this is not easy on us to smash them all the time too," he said.

"We have to make them fit as well as fresh."

However, there is a sense of growing frustration among the playing group over the lack of results, with skipper Mitch Duke telling Fox Sports the speculation Babbel could be sacked has been felt within the team.

"There's been a sense it came to the point a couple of weeks ago, he was like 'I could either throw in the towel and give up or I can keep fighting'," Duke told the broadcaster.

"He said it's not in his nature to give up. He wanted to keep going. He's passionate, he loves football even now as a coach. He's passionate and he doesn't want to give up. He's a fighter to the end.

"He's made that clear and he wants us to look in the mirror and have that same demeanour about ourselves. Unfortunately we're not quite putting it out on the pitch and she's getting frustrating."

Following the departure of marquee signing Alex Meier last week, replacement striker Simon Cox is expected to lift the team when he takes the field in the coming weeks.

Australian Associated Press