It might not have been planned, but the events of 2020 have produced a version of the Champions League knockout phase that could well be a breath of fresh air.

In exchange for traditional heavyweights going head-to-head over two legs, the quarter-finals will each consist of one match, in the neutral surroundings of Lisbon.

What's more, six of the eight teams have never won the tournament, including Atalanta and Paris Saint-Germain.

They're not really comparable for their approaches off the pitch: Atalanta's record signing, Luis Muriel, cost less than a 10th of the fee PSG paid for Neymar. Still, these are two teams going toe-to-toe this season when it comes to entertainment value.

Using Opta data, we examine why Atalanta versus PSG could be a truly spectacular showdown - and why the potential absence of two star names could spell major trouble...

GUNG-HO OR GO HOME

At PSG, Thomas Tuchel is under pressure to deliver attacking as well as winning football, in the Champions League more than anywhere else. Atalanta just seem to know no other approach.

Only Bayern Munich (31) have scored more goals in this season's competition than PSG (20), and Atalanta are only four goals back.

Of the teams left in the tournament, Bayern (23.23) have the best minutes-per-goal rate. PSG are second on 36, with Atalanta third on 45.

PSG's knack for scoring should come as little surprise since they have the best shooting accuracy (26.32 per cent) of all the quarter-finalists. Atalanta are strangely much lower down at 17.58, although that's perhaps a figure that is skewed by their number of attempts: they have managed 80 shots inside the box compared to PSG's 42, and 28 outside the area, with PSG on 29.

PSG also benefit from a high number of big chances created (31), with only Bayern (37) and Manchester City (38) creating more. Atalanta are fourth on that list (26), but for overall chances created, they are better than PSG - they have carved out 81 openings, 10 more than the Ligue 1 champions.

ANY CASE FOR THE DEFENCE?

Perhaps Atalanta have little choice but to keep things on the front foot. They have only kept two clean sheets in their eight games this term and have conceded 16, which is more than any other remaining side.

PSG, meanwhile, have kept more clean sheets (six) and conceded fewer goals (four) than anyone else. It seems that, when necessary, they know how to sure things up. Having said that, they have faced 97 shots this term, which is just four fewer than Atalanta, so perhaps luck - and goalkeeper Keylor Navas - have been on their side.

Attacking football might be a given on Wednesday, but these are still teams who know how to disrupt. PSG have won 118 free-kicks in this term's competition, more than any other quarter-finalist and 24 more than Atalanta. Additionally, Atalanta have conceded 123 free-kicks, the most of any team in this season's tournament. Check your shin pads, Neymar.

ILICIC, MBAPPE AND FEARS OF OVER-RELIANCE

Kylian Mbappe is battling to recover full fitness after having injured his ankle in the Coupe de France final win over Saint-Etienne.

It looks likely that the France forward will be able at least to be on the bench for PSG, but Atalanta have no such luck when it comes to Josip Ilicic, who is definitely missing Wednesday game due to a personal matter.

Mbappe and Ilicic have each scored five goals in this season's Champions League, the latter getting all four in the last-16 second leg win over Valencia. Mbappe has four assists to boot, having created five big chances, two more than Ilicic.

Both have been involved in more goals for their respective sides than any other player, but the loss of Ilicic - playing the best football of his career at the age of 32 - looks like being a far more damaging blow.

Ilicic has a big chance conversion rate of 80 per cent, a shooting accuracy of 81.82 per cent, and has completed 83.05 per cent of passes ending in the final third. All of these are leading figures for Atalanta this season.

He has also completed 21 dribbles, again the best of anyone in Gian Piero Gasperini's side and 11 more than Mbappe has managed.