Celtic's 10-in-a-row hopes appear all but over after Saturday's 1-0 defeat to Rangers at Ibrox left them trailing Steven Gerrard's team by 19 points.
Hoops boss Neil Lennon and his team still have three Scottish Premiership games in hand and two Old Firm derbies remaining this term in which to turn around their campaign – but it looks a forlorn hope.
Here, the PA news agency takes a look at where it all went wrong for the champions.
Celtic had two priorities over the summer; securing a top-class goalkeeper and adding a no-nonsense centre-back to beef up their back four – but they failed on both fronts. So much time was spent on the failed bid to lure Southampton's Fraser Forster back for another loan stint that Craig Gordon was allowed to slip out the door unnoticed and rejoin Hearts. Greece international Vasilis Barkas then reportedly cost the champions £5million but has barely made a notable save in his first six months, meaning Scott Bain and Conor Hazard have both been given a go by Lennon in a desperate search for a steady pair of hands. Ireland captain Shane Duffy was expected to add some steel in the centre of defence but his loan switch from Brighton has been a disaster, with Lennon only throwing him into the fray during Saturday's Ibrox defeat when Nir Bitton – a midfielder starting at the back – was sent off.
Injury and fitness woes
There were warning signs things were not going to plan from the off when Lennon issued Leigh Griffiths a furious public dressing down after the striker returned for pre-season "out of condition and overweight". It took the Scotland frontman another two months to work himself back into the team and he has still only made five starts so far after being held back by a knee injury. Albian Ajeti – a costly recruit from West Ham – started with five goals in his first 10 outings but has also struggled to get up to the pace amid lingering fitness issues, while a stress fracture picked up by James Forrest back in September was another big blow to the Hoops' 10-in-a-row dreams.
Player commitment questioned as Celts crash out
Lennon hit out again at sections of his squad as the Parkhead men were sent tumbling from the Champions League by Ferencvaros, claiming a number of his star men were trying to engineer their Parkhead exits. He said a number had been "making waves to leave the club" and washing that dirty laundry in public did nothing to dispel the notion that cracks were appearing within the Celtic ranks. Fingers were pointed at the likes of Odsonne Edouard – who sat out the game with injury – Kristoffer Ajer and Olivier Ntcham and while all three have continued to play a major part this term, the Celtic faithful remain suspicious about their long-term commitment to the cause.
Boli Bolingoli did not hang around too long after his unauthorised trip to Spain, followed by his decision to play in a game against Kilmarnock without first informing the club that he had breached strict Covid-19 rules by flying overseas. He secured a move to Turkey but the consequences could be far reaching for the Hoops. They were forced to postpone games against Aberdeen and St Mirren by First Minister Nicola Sturgeon, allowing Rangers to build up a lead at the top they have so far been unable to close. There were more coronavirus problems ahead of the opening Old Firm game as Edouard tested positive while on France Under-21 duty and Ryan Christie was forced to self-isolate after a Scotland trip. Without the duo, Lennon's team fell further behind as Steven Gerrard's Light Blues won the opening Old Firm derby of the campaign.
That derby defeat sparked a catastrophic run of results in which Celtic's season fell apart. During a run of 12 games they won just twice while shipping 28 goals as their defensive line crumbled time and again. Sparta Prague twice hit four goals against the Glasgow giants, while AC Milan managed seven over two games as vulnerabilities were exposed without mercy. They finished bottom of their Europa League section having given away 19 goals over six fixtures – leaving them tied with Ludogorets and Dundalk for the most goals conceded in the group stage. League points were spilled in draws with Aberdeen, Hibernian and St Johnstone, while a shock Betfred Cup exit at the hands of Ross County was ultimately the spark for furious protests outside as angry fans demanded Lennon leaves. The Northern Irishman has clung on – but the board have promised to review his position this month.