Simunovic hadn't played for Celtic since late September before Wednesday.
Jozo Simunovic may have only just returned following a seven-week absence, but some Celtic fans do not believe that should excuse the Bosnian's Paris Saint-Germain performance.
Simunovic and co shipped seven goals at the Parc des Princes, after Moussa Dembele had fired Celtic ahead within the first minute.
The Champions League encounter was the centre-back's first since September's Old Firm win at Ibrox, and his return had generated some excitement in the build up.
But while many Celtic supporters are prepared to let Big Jozo off the hook, others have gone as far as suggesting he should be replaced in January.
Here's how they reacted to his latest injury comeback on social media...
What? Lol. Boyata has been far better and far more reliable that Jozo. https://t.co/B5F5xMgIxq— 64 and counting! (@cfcss85) 22 November 2017
Jozo’s time is up now. Two centre halves in January please. And a defensive coach who can organise them— Kenny Campbell (@kenny_campbell) 22 November 2017
Embarrassing to many imposters the night— peter (@w33pmg) 22 November 2017
There was no excuse for tonight’s passive performance. Not one challenge of note on naymar and I was sure I saw KT holding cavani’s newspaper for the 5th! Jozo was certainly applauding the 7th.— Noody (@Noody69Noody) 22 November 2017
He was bad first half good 2nd . Jozo the worst— F.I.M.mcCool (@frasermecu) 22 November 2017
Jozo was also poor, but they all struggled, tbf it's not surprising they are constantly on high alert with Frank Spencer playing it out from the back, given the way manager wants us to play, Gordon is worst keeper in 15 years— Richard Murphy (@RichardMurphy80) 22 November 2017
Boyata is poor and Jozo can't dine out on launching Kenny Miller into orbit anymore.— JuneBhoy67 (@JuneBhoy67) 22 November 2017
Having watched the highlights I'm not sure bringing Jozo back for his first game in months against possibly Europe's best team was a great decision.— Lachie Mor (@LachieMor1) 22 November 2017
Big jozo.good as he is a think it may be time to move him on.we have no continuity in defence with his injury woes.has he ever played 5iar for us?— Brian L (@BlakFrancis) 23 November 2017
Boyata, Simunovic and Bitton were laughably poor last night - yes PSG are good but those 3 were awful - sometimes not even looking at the ball— Pol MacFhionnghaile (@mcginleybhoy) 23 November 2017
Simunovic was a passenger. Cannae stay fit so needs punted anyway. New gk a must also. After our goal should have been fighting gid everything. Way too passive & submissive— Bryan McGlynn (@bmcglynn78) 23 November 2017
Boyata and Simunovic don;t want to be here. Lustig does, but he's in a comfort zone.— Richard McGinley (@Richiestoke) 22 November 2017
We seem to forget how to defend in European games. Do we need to replace simunovic and Boyata? I think so, especially if Boyata won't sign a new deal and simunovic wants to move to prem.— Liam Reilly (@LiamReilly1503) 22 November 2017
Celtic, who suffered a 5-0 to the same opponents at Parkhead two months ago, were put to the sword by goals from Neymar (two) Edinson Cavani (two), Kylian Mbappe, Marco Verratti and Dani Alves.
Brendan Rodgers' side could not progress to the competition's last 16 regardless of Wednesday's result, although anything less than a three-goal defeat against Anderlecht next month will secure their passage into the Europa League.