Martin O’Neill leaving Celtic would not surprise Paul Lambert, but the former club captain would be “shocked and disappointed” if the manager was to be sacked.

The 74-year-old said he would use the international break to take stock following back-to-back defeats by Rangers.

Those Old Firm setbacks came either side of a home loss to Ferencvaros in the Europa League, while there was a shock Champions League collapse to LASK in August, with a 4-0 aggregate lead surrendered.

“I will reflect on the games,” said O’Neill, who was made permanent manager for a second time in the summer after two stints as interim boss last season resulted in a league and Scottish Cup double.

O’Neill, who won another seven trophies with Celtic from 2000-05, when Lambert was playing, added: “I’m not immune from criticism. Absolutely and utterly far from it.

“I think there’s every reason to ask ‘can you turn this round? Can you change the whole thing?’ I have to kind of look at the bigger picture at this minute.”

Lambert insists O’Neill is Celtic’s best manager since the great Jock Stein, but the 57-year-old added: “It wouldn’t surprise me if he left. I don’t think he needs it.

“I’d be shocked and disappointed if Celtic sacked him.

“I think they give him the option, if that’s what’s on his mind, if he did want to walk away.

“He’s got enough credit in the bank. It wasn’t that long ago people were shouting for a statue for him, so I don’t think you can go from one extreme to the other.

“If he wants to go, then he goes himself.”

O’Neill steadied the Celtic ship twice last term following the departures of Brendan Rodgers and Wilfried Nancy.

“They were hanging on by a thread and he turned that around,” is how former Ipswich Town and Norwich City manager Lambert described the impact of his former boss.

“There was only one person who could rescue Celtic last season and he did that.

“I’d bet any money that he hasn’t changed anything from how he was then.”

Lambert was critical of individual performances in the defeats by Rangers as well as the remarks of defender Cameron Carter-Vickers, who spoke of playing “too random” and “getting a script and sticking to it”.

“The players need to take responsibility,” he told BBC Radio Scotland. “I watched the game and dear oh dear…

“That was cringeworthy, the stuff from Carter-Vickers. I thought ‘hang on, you’re not making a movie’.

“Solve the problem yourselves. When something is not going right, you look to rectify it, you don’t look to a manager to say ‘do this or do that’.

“I thought that was bang out of order, coming from someone who’s been a decent player for Celtic.”