Celtic have known nothing other than domestic success since Brendan Rodgers replaced Ronny Deila as the club’s manager in May, 2016.

He became the first boss to win consecutive trebles (the first of which was delivered without losing a game) and appeared to be on course for a third after defeating Aberdeen in this season’s BetFred Cup final on December 2.

However, dismal results away from home combined with poor recruitment in the last year have seen Rangers draw level with them on points at the top of the Ladbrokes Premiership table, courtesy of Rodgers’ first defeat in the derby at Ibrox on December 29.

An eighth consecutive championship is no longer guaranteed and former goalkeeper Pat Bonner, who spent 17 seasons at Parkhead and is now a BBC pundit, believes that there will be no hiding place for Rodgers and the club’s chief executive, Peter Lawwell, should Celtic fail to use their vastly superior wealth to deliver 10 in a row.

“The fans won’t forgive them – Peter Lawwell more than Brendan, probably – if they don’t win 10 in a row, given the position of strength they were working from and how close they are to doing it,” he said.

“Most Celtic supporters won’t remember Jock Stein’s nine in a row but they’ll have lived through Rangers equalling it and now they want to see it surpassed.

“The league is undoubtedly the big thing this year. I would forget about the treble and just concentrate on winning that eighth successive championship – a double this season would be enough.

“After that they can take stock and ask where they should be going in the next couple of years. Does Brendan stay? Because if he does then the board must back him properly.”

In spite of the undoubtedly impressive achievements of 2016-18 (which included twice reaching the group stage of the Champions League, generating £60m in additional revenue), Bonner suspects that they will be forgotten should the current squad falter in the quest for that perfect 10.

“Unfortunately, that’s the way it is,” he said. “Celtic and Rangers created the benchmark with their history of winning trophies and you have to keep doing that every season.

“Even now, with the top of the table as tight as it is, the expectation from the Celtic fans is that they’ll win another treble this season.”

Rangers posted record losses last year while Celtic’s European exploits saw them record a £17.3m profit – which didn’t include the £20m sale of Moussa Dembele to Lyon – but Bonner insists that supporters will take no succour from spreadsheets should their team finish anywhere other than in first place this season.

“No matter how much money you have or how many trophies you’ve won recently, it still all comes down to what you do on the pitch,” he said.

“There’s no question that Rangers have made strides, but if they can get back to playing as well as they were before the defeat at Ibrox, Celtic should still win more games than the rest.”

Celtic have already signed Steve Gutman and Vajkoun Issouf Bayo on permanent deals and taken Timothy Weah and Oliver Burke on loan during the January window while Rangers have brought in veterans Steve Davis and Jermain Defoe.

“I’m not sure about the signings so far,” said Bonner. “We’re talking about young boys, after all, which appears to be the club policy.

“The big question for Brendan is whether he perseveres with Scott Brown in the holding role or puts Callum McGregor, who had the team playing so well when he was in that position, back in there.

“It’s the biggest decision he has to make. Kieran Tierney is going to be out for a while, Mikael Lustig is running out of steam, Dedryck Boyata will be away in the summer and Filip Benkovic’s loan will end then.

“The biggest disappointment for the fans has been the failure during the two previous transfer windows to bring in three or four players in key positions who would now be ready to go.

“Celtic missed a trick during the summer, when they could really have consolidated their position as the biggest club in the country. Instead, they’ve really been struggling up front and, in midfield, it looks increasingly like the energy of John McGinn could have made a difference if only they’d been able to get that deal done.”

It is, of course, not all doom and gloom for the champions, but Bonner insists that they cannot afford to take their eye off the ball in the weeks and months ahead.

“The League Cup is already in the bag and I still think that they’ll probably win the league because the winter break came at the right time for them,” he claimed.

“It’s given them the chance to step away for a bit and refresh themselves and their first four matches once they come back are all winnable ones at Parkhead while Rangers are away to Kilmarnock, Livingston and Aberdeen during that period.”