Scottish champions Celtic are currently preparing for a crucial Champions League group stage showdown with Bundesliga side RB Leipzig, with the Old Firm outfit's hopes of progression currently hanging by a thread ahead of Tuesday's meeting at Parkhead.

A key talking point heading into that potentially vital encounter is the form of goalkeeper Joe Hart, with the former England number one having faced scrutiny for his role in the defeat to the German giants a week ago.

The 35-year-old made an uncharacteristic mistake to gift Marco Rose's side a second goal on the night, with the Hoops having only just gotten themselves level moments earlier through Portuguese gem, Jota.

The Shrewsbury-born stopper had produced an errant pass straight to the feet of Dominik Szoboszlai, with the Hungary international duly teeing up teammate Andre Silva to fire the home side back in front.

Following that blunder, the veteran ace had admitted his "mistake" that was ultimately "punished" by such clincial opposition, with that error having come just days after the former Manchester City man was involved in a mix-up with defender Josip Juranovic during the narrow victory over Motherwell.

A poor week in relation to the lofty standards that the £23.5k-per-week man has set during his time in Glasgow over the past year or so, although calls for the 75-cap gem's head do appear rather premature, particularly following his impressive form up to now.

Pundit Frank McAvennie was notably critical of the goalkeeper's performance last week, stating that it was an "embarrassing" error by such an experienced figure, while also teasing a possible starting berth for summer signing Benjamin Siegrist by suggesting that the Bhoys have a "damn good keeper in the wings."

To drop the £1.53m-rated man - who arrived from Tottenham Hotspur last summer - would seemingly be particularly harsh such has been his crucial role in recent times, with Hart having kept an impressive haul of 31 clean sheets in just 66 games in all competitions for the Scottish Premiership side.

That tally includes five clean sheets from just nine top-flight games so far this term, with the evergreen talent showcasing his resilience to produce a fine stop to deny Stevie May in the recent, dramatic victory over St Johnstone.

On a day in which the 6 foot 5 titan had little to do in Perth - having made just two saves against Callum Davidson's side - that rare intervention showcased his ability to stay focused when it is his side largely in control, with Postecoglou no doubt in need of such an experienced head to be relied upon in the sticks.