The Hoops have booked a pre-season camp in Wales but it remains to be seen if Postecoglou will able to report for duty in time for their July 5 arrival.

The delay is yet another frustration for the Celtic support, who are already deeply unhappy with the length of time it has taken for the club to appoint Neil Lennon's successor following the Northern Irishman's resignation in February.

Former Parkhead favourite Lambert agrees the quarantine requirements will present Postecoglou with a minor headache but he expects the former Socceroos head coach to have been fully briefed on the squad he is inheriting by the time he arrives.

The former Hoops midfielder told Sky Sports News: "If it is quarantine and it's all true that he's coming and will have to do quarantine it'll be difficult in that aspect but I'm pretty sure the club will have informed him which players he will be left with, what ones are going to go, which backroom staff.

"I'm sure he'll know what's going on even though he won't be able to do much because of the situation. But hopefully they've got the right guy in there."

UEFA confirmed last week Celtic have applied for an exemption to rules requiring bosses coaching teams in the Champions League to have a Pro Licence.

Postecoglou may not have the required certificate but he is not short on experience having won a number of trophies in his homeland and in Japan.

And Lambert has backed him to pleasantly surprise the Hoops supporters who fear this appointment will be a massive step down after missing out on number one target Eddie Howe.

"It's great news for everybody in Glasgow, the Celtic support especially," Lambert said. "It's been a long time but hopefully they've got the right guy and he goes and rescues the title back.

"I think that's important that he puts his own mark on it, which I'm pretty sure he will do, find his feet pretty quickly in the goldfish bowl as they call it up there.

"I was never under any pressure on who they were going to appoint but whoever it is will have to win football matches."