Frank McAvennie has urged Celtic to go all out to sign Shane Duffy after the shock Champions League qualifying defeat to Ferencvaros.

Speaking exclusively to Football Insider correspondent Dylan Childs, the former Parkhead star ripped into Christopher Jullien and Kristoffer Ajer for their performances on Wednesday night.

As revealed by Football Insider, Brighton have rejected a seven-figure loan fee from the Hoops as they hold out for a £2million-plus sum for the 28-year-old.

It is understood the Bhoys are not willing to pay more than £1million for the 6ft 4in [Transfermarkt] Republic of Ireland international.

McAvennie blasted what he saw from the Bhoys’ current centre-halves at Parkhead and insists that Lennon needs an imposing defender like Duffy at the heart of his defence.

McAvennie told Football Insider: “I cannot understand the centre-halves. I just do not get them.

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“Why not go and buy a big defender? Go and get Duffy. Do not argue. Just go and get him. They could have done with him last night.

“Duffy would have been talking to the other defenders. He would have been talking to (Greg) Taylor and told him to hold.

“Taylor is a young boy, I don’t blame him but sometimes he gets overzealous and you need someone like Duffy to tell him, ‘Where are you going? Get back in there!’ That is their job. Everyone has a job.”

Lennon has used Ajer, Jullien and Nir Bitton at centre-back this season, while Hatem Abd Elhamed has also played as part of a back-three in the past.

Duffy, who played 21 times for Brighton last season, is set to be behind the likes of Lewis Dunk, Joel Veltman and Ben White in the pecking order if he stays with the Seagulls for the new campaign.

In other news, Celtic have agreed the terms of a blockbuster signing after medical completed.