1. Scott Brown is a problem
There's no doubt that Scott Brown is a Celtic legend. An ceaseless central midfielder who has played over 400 games for the Hoops since joining them all the way back in 2007. Moreover, he's now club captain.
But there can be no doubt that Brown as he is presently is a problem for Celtic. At 32 he's clearly past his prime, but his presence as an influential figure and leader makes it hard for Brendan Rodgers to drop him.
Yet today showed exactly why he must do just that. With Celtic leading 0-1 in Paris, Brown foolishly and needlessly gave the ball away wiith a sloppy pass. He then tried to break Adrien Rabiot's ankles to stop the ensuing PSG counter but he's so past-it even his lunge was easily avoided. Rabiot found Neymar, and bam, 1-1.
Sure, the end result was so emphatic it's likely that PSG would have always come back to run Celtic ragged, but for your captain and most experienced player to make it so easy for them? That's embarrassing. As is Brown's current reputation in these big games as a man who simply runs around kicking people. If Celtic want to progress they may well have to move on from Scott Brown and find a more dynamic midfield general.
2. Celtic need a top quality centre-back
This may be stating the obvious but the way in which Celtic's centre-backs collapsed under the pressure of the PSG attack was embarrassing. None of them was all that great at handling their men 1v1, but whilst you'd expect that they didn't manage to even be well organised either.
Dedrick Boyata perhaps stood out the most as he was the central defender, the role most often associated with the organiser and Boyata appeared to be anything but. Celtic are badly in need of another bit of scouting genius like the one that saw them land Virgil Van Dijk back in 2013.
If they could do that, find a centre-back who can not only handle himself against top-quality opponents but also organise the defence; someone like Heerenveen's Jerry St. Juste perhaps, then they could give teams like PSG more of a fight.
3. Moussa Dembélé is destined for greatness
It's perhaps stating the obvious but Moussa Dembélé is a special talent. He's scored 39 goals in his 62 games for Celtic at the tender age of just 21. He's got the pace, power and precision skill to make it for any side in the world.
Against PSG all of these attributes were on display. Dembélé gave Celtic a shock lead with a crisply taken finish inside of a minute, moving so well into space and firing past Areola.
Dembélé failed to build on that goal but that was mostly because as he often had to run against the entire Parisian defence by himself. Still, his goal alone was proof this kid has got what it takes to go all the way.