Known for his inability to win trophies at Tottenham, Maurico Pochettino has already won one during his stint at PSG and will be hoping to add the Champions League to his cabinet.
Pochettino will have to complete the job without the impressive Moise Kean, who is currently quarantined with coronavirus. The on-loan Everton forward scored in the first-leg and has been a vital cog in this PSG side.
However, Angel di Maria is back from injury and will likely take Kean's place on the right-hand flank.
Alessandro Florenzi has also returned to full fitness and could partner di Maria on that right side, with Florenzi at right-back.
Pochettino rested several stars in the French Cup victory over Brest, but expect all the big guns to return, with Keylor Navas, Presnel Kimpembe, Marquinhos and Layvin Kurzawa all to come back in.
A midfield three of Marco Verratti, Idrissa Gueye and Leandro Paredes worked wonders in the first-leg so expect a similar role to be performed by them again.
Mauro Icardi will be up front, with hat-trick hero Kylian Mbappe playing off the left and cutting inside just like in the 4-1 win.
As for Barcelona, Ronald Koeman has played a 3-4-1-2 system recently, but with Jordi Alba out after suffering an arm injury against Osasuna, Junior Firpo will have big boots to fill.
A back three of Oscar Mingueza, Samuel Umtiti and Clement Lenglet have performed well in the absence of Gerard Pique and Ronald Araujo, so it's likely they'll start again.
Sergino Dest and the aforementioned Firpo are the expected wing-back pairing, with Frenkie de Jong and the ageing Sergio Busquets in the middle of the park.
Pedri has performed far beyond expectations, and they now rely on the youngster so heavily; he'll need to perform well if they have any chance of a comeback.
The partnership of Lionel Messi and Antoine Griezmann struggled last season, but recently it's flourished, and Messi will need another one of his magical nights to save their season.