Frank McAvennie has blasted the Celtic defence, branding them not good enough – even after the Aberdeen win.

The former Celtic player is not at all happy with Ange Postecoglou’s inverted full back system and has made it clear what he thinks about the defence.

“Turnbull should not have been in that position.” Macca told FI.

“He was in the right-back position and Ralston should have been there.

“How many times can I say it? These defenders are not good enough. They just aren’t good enough.

“Turnbull made a massive error, yes. But get off his back. He should not have been there.

“He was covering because Ralston, as usual, was out of position.

“These are the things we need to fix.”

He’s not wrong about the calibre of players needed to play a high intensity and complex system.

We have said it before about some of our back line, they don’t seem able to cope with what’s being asked of them and our two centre-backs can become exposed very quickly.

Ralston runs through brick walls for the team but has his limitations. Juranovic is the man to come in and take the right-back spot but he’s not had a clear run at things with fitness and now an injury stopping him from really making the position his own.

Left-back – we have a novice in Adam Montgomery who looks promising but will be overexposed if we can’t find better options in the position.