Another bruising evening on the continent for Celtic ended with fingers pointed at keeper Vasilis Barkas.
The £5million shot-stopper, signed from AEK Athens, has endured a difficult start to his Parkhead career.
The 26-year-old has looked shorn of confidence at times and found himself being dropped for Scott Bain before returning to the fold in recent weeks.
It must be said, Barkas hasn't had the easiest of beginnings to life in Scotland. Heading to a new country in the middle of a pandemic and playing behind a back four that is struggling mightily, settling in to that is no simple task.
But Celtic 's need is great and time is a precious commodity in the bid to turn this season around.
A report on Friday claimed the club will look at bringing in another keeper come the January window.
Here, Record Sport Online looks at five they could target.
Dean Henderson
Henderson is highly-regarded at Manchester United and won't be available for anything other than a loan, if at all.
Rumours have been swirling that Celtic could move for him after the New Year, with David de Gea clinging on to the number one jersey.
Ole Gunnar Solskjaer recently insisted Henderson wants to remain at Old Trafford, but didn't quite specify whether he meant short or long term.
The 24-year-old may well want to fight De Gea for the shirt he seems destined to inherit one day, but as the clock ticks down to Euro 2020 he'd been forgiven for favouring another temporary stint away to keep the attention of Gareth Southgate.
Paulo Gazzaniga
The Argentine has been shunted down to third-choice at Tottenham, thanks to the arrival of Joe Hart.
Gazzaniga is well-liked in North London, however, and has been viewed as a reliable option in the absence of number Hugo Lloris.
At just 28, he's unlikely to be all that content sitting well down the pecking order and reports have claimed Jose Mourinho could be willing to let him go in January.
The chance to step straight into the void at Celtic may well appeal and a loan deal might just be the best arrangement for all parties.
Fraser Forster
The deal that never was from last summer could be worth revisiting in the coming weeks.
Another season at Parkhead looked ideal for Forster after a sensational return in 2019/20. He rejoined Neil Lennon 's side from Southampton and was instrumental in domestic and European successes.
However, the big shot-stopper turned down the chance to stay at Celtic to fight for his place at Southampton.
But he's yet to make a single appearance for Saints and could well be regretting the decision to stay down south.
His perceived snub stirred some bad feeling among the Celtic support but, given the current situation, you'd imagine the majority would happily put that aside if an agreement can finally be struck.
Benjamin Siegrist
The Dundee United star has emerged as one of the top keepers in the Premiership and it's been reported Celtic watched him in a recent clash with St Johnstone.
Convincing any side to part with their number one midway through a season is challenging and United would demand to be healthily compensated for the 28-year-old Swiss.
He's relatively inexperienced in the top-flight but has looked more than comfortable with the step-up, impressing against Celtic among others, despite conceding a late sickener.
January is a notoriously tricky time to pull off decent deals and Siegrist could represent decent value in a difficult market.
Caoimhin Kelleher
The young Liverpool keeper was thrust into the public eye in midweek with an impressive Champions League performance against Ajax.
He pounced on an opportunity to deputise for the injured Alisson Becker and certainly didn't disappoint.
But, at 22, his path to the number jersey remains a tricky one. Jurgen Klopp still has Adrian on his books and was this week linked with a move for Sevilla's Alfonso Pastor.
If it's first-team action Kelleher craves then a loan switch to Celtic could be just the ticket.
Kelleher was due to leave on-loan during the summer until injury concerns arose over Alisson, so anything materialising in January could depend on the Brazilian's fitness.
