Adelaide coach Gertjan Verbeek has ripped into his players following a fourth straight A-League loss, with makeshift defender Ryan Kitto copping most of the heat.
The Reds dropped out of the top six following Saturday's 3-0 mauling at the hands of Perth Glory at HBF Park.
Kitto, whose preferred position is in midfield, started the match at left-back but was subbed out at half-time following a series of mistakes.
Verbeek was frustrated at the way Glory attacker Joel Chianese was able to spin past Kitto in the 26th minute to open the scoring.
Such was the glut of chances, Glory could have easily ended the match with five or more goals to their name.
Verbeek said the team's performance simply wasn't good enough, and he was particularly brutal when talking about Kitto, a 25-year-old with 96 A-League games to his name.
"Kitto has played for a long time in the beginning in that position, so he had to know what to do," Verbeek said.
"We trained on Thursday and the tactic was ok, the plan was ok, and I think the plan worked.
"We didn't give much away but the things we gave away were 100 per cent chances for them.
"You see how easy the striker from Perth is turning away from Kitto. That's not defending enough.
"We're talking about the A-League, we're not talking about the youth team or the NPL. You can't make those mistakes in the A-League."
If Verbeek manages to survive the axe by turning around Adelaide's fortunes, Kitto may struggle to retain his spot on the list despite signing a two-year contract extension in October.
"The mistakes are personal, and (when the) players make them too often, they show me that they're not good enough for the A-league," Verbeek said.
"So that's why I (subbed) Kitto. It's hard for him, but he wasn't (just) making one mistake - after that he was making many mistakes, and he got changed.
"For next season we have to see if he can make it. But that's for next season. This season we have to do it with this squad, and up until now I'm not happy with what I'm seeing."
Seventh-placed Adelaide will host the sixth-placed Melbourne Victory at Coopers Stadium next Friday night.
It's a game that could prove crucial to the finals fortunes of both sides.
Verbeek was at a loss for answers to his team's woes after the loss to Glory.
"It's the fourth game we lose, so we don't learn from the (other) games we played," Verbeek said.
"That's something that we have to work on, and in this moment I don't know how."