Les Parisiens and the Cityzens made it to the knockout stages last year as well, and while City were eliminated by Olympique Lyon in the quarter-finals, PSG made their way to the finals where they lost to Bayern Munich.
PSG had a relatively rocky start to their domestic and European campaigns due to a host of injuries and due to COVID-19. However, they've recovered excellently and are still on course for a potential double this season as they sit just a point behind LOSC Lille in the league standings and are into the last four of the UCL.
They demolished Barcelona by an aggregate score of 5-2 on their way to the semi-finals, along with a high-octane six-goal tie against Bayern Munich which saw them go through on away goals.
Manchester City had a similarly slow start to their league campaign but once they they got going, their rivals found it difficult to keep pace with them. Guardiola's unstoppable side currently hold a ten-point lead over the closest contenders, Manchester United, and they recently emerged victorious at Wembley to win the EFL Cup.
The soon-to-be crowned Premier League champions comfortably saw-off Borussia Monchengladbach in the round of 16 before a tie against Borussia Dortmund where Phil Foden fired them through with two late winners across both legs.
It is a battle between two sides trying to win their first UEFA Champions League and they've spent hundreds of millions so far to achieve their goal, albeit faltering every single time. With City and PSG in the semi-finals and both sides in red hot form, it's bound to be a great battle between Mauricio Pochettino and Pep Guardiola's sides.
On that note, here is a look at the best combined XI from available players for both sides.
Goalkeeper: Keylor Navas
There's no denying that Manchester City's Ederson Moraes has had a superb season so far. In fact, City boast of the best defence in Europe with the highest clean sheets in Europe so far. However, Keylor Navas gets the nod in this line-up simply because of the number of times he's kept PSG alive in the UCL this season with crucial saves.
Navas has faced 54 shots on target in the competition this season — more than any active keeper in the competition, and more than thrice the number Ederson's faced — and still maintained a remarkable 85.2 save percentage as he's stopped 45 of them. This includes a penalty in the round of 16 against Leo Messi.
The Costa Rican has been phenomenal between the sticks for PSG and has arguably been the best keeper in the UCL this season.
Defence: Kyle Walker, John Stones, Ruben Dias, Joao Cancelo
There could be a very good case made for John Stones and Ruben Dias potentially being the best central defensive partnership in Europe this season.
Stones' career at Manchester City appeared all but over before this season but the Englishman has made an incredible comeback for his side, playing his way back into City's XI and, subsequently, Gareth Southgate's squad.
Ruben Dias' arrival at the Etihad has proven to be the catalyst behind this incredible turnaround for Manchester City's defence. They made the Portuguese star one of the most expensive players in their history to strengthen their backline, and have begun to reap the rewards for their faith in him.
Dias has arguably been one of the best central defenders in the world since his move to Manchester City. His reading of the game, ability on the ball, and aerial presence have all been simply incredible. Most of all, he's the sort of leader at the back that the Cityzens have lacked since Vincent Kompany left the club.
Stones and Dias have formed one of the most formidable defensive partnerships in the world and complement each other's styles very well. City have only conceded 24 goals in 33 league games, with five of them coming in one game against Leicester City. They occupy the two central spots over Presnel Kimpembe and Danilo Pereira.
Walker has been consistent with his displays and has been Guardiola's go-to right-back for crucial games. Whether it's inverting into midfield, playing as part of a back-three, or a conventional full-back — he has operated steadily across all set-ups for the Catalan.
Cancelo's unique skill-set has added an element of unpredictability to City's approach this season. He's operated higher up the pitch almost as an additional playmaker in midfield, showcasing his excellent close control and passing range to go with his defensive side. While he's a right-back by trade, Guardiola has used him on the left on several occasions, paving the way for him to come into this XI.
Midfield: Kevin De Bruyne, Marco Verratti, Phil Foden
Another area of the pitch that's dominated by Manchester City is the midfield. Kevin De Bruyne's place in the side was never in question as he is, simply put, one of the best players in the world across any position.
The Belgian star is one of the most complete players in Europe. His passing range, vision, goal-scoring and set-piece prowess barely scratch the surface of what he's capable of on the pitch. No player remaining in the competition has registered more assist than De Bruyne's four and he's effortlessly pulled the strings during City's rampant UCL run so far.
After De Bruyne, no player has been involved in more goals for City this season than Phil Foden, who is the next player in this midfield. The English prodigy has been around for a while now but his performances for City this season have been too good even for Guardiola to ignore.
Foden been magnificent every single time he's taken to the pitch, irrespective of who he plays against, who plays with him, and where he's deployed. He's been a joy to watch and he's managed to come up clutch for his side as well. The 21-year-old scored a 90th-minute winner against Borussia Dortmund in the first-leg of their quarter-finals, a 75th-minute winner in the second leg, and set up Ilkay Gunogan's winner against Gladbach.
The City pair will be supported by another brilliant player in Marco Verratti. The Italian maestro is widely regarded as one of the most efficient players in the world with the ball at his feet, constantly keeping the play ticking in midfield.
The metronomic midfielder has been phenomenal for PSG whenever he's fit and available, and will be a player City could have a hard time stopping. His close control, vision and execution from even some of the most difficult angles gives PSG an edge in midfield and helps them keep control of proceedings.
Verratti has spent a considerable while on the sidelines this season due to injuries and contracting COVID-19, but he's regained his fitness and will be available for the game against City.
Attack: Angel Di Maria, Kylian Mbappe, Neymar
In contrast to the defence and midfield of this XI, the attack is completely dominated by PSG's star names — and with good reason.
While Riyad Mahrez has had a great season so far, it would be harsh to overlook Angel Di Maria's superb displays for the Parisiens, particularly in the latter stages. The Argentine put in a massive shift for PSG against Bayern Munich and set up the eventual winner in their five-goal thriller at the Allianz Arena.
The ex-Real Madrid man is one of only two players in the PSG side to have won a UCL title and he's used all his experience to roll back the years and deliver consistent performances for them. Di Maria's work ethic has also stood out as he's also helped out when his side have been caught on the counter. His three assists are only bettered by De Bruyne's four among active players, along with Mbappe.
Di Maria will be joined by Neymar and Kylian Mbappe to complete the attack of this combined XI. The Frenchman and the Brazilian – two of football's most expensive purchases ever — are two breathtaking individuals on the football pitch, capable of things that many could only dream of.
Neymar and Mbappe have been in sublime form over the course of the 2020/21 campaign, forging a partnership deadly enough to cut through even the most organised defences in the world. Bayern Munich's backline had a nightmare trying to contain the prolific duo, and Neymar put in what is, perhaps, one of the best attacking displays of the season without scoring a goal.
When Neymar was injured, Mbappe stole the show as he blitzed Barcelona on their own turf with a stunning hat-trick. After running the Catalans ragged, he scored another in the reverse fixture, becoming the first-ever player to put four past the Blaugrana in a UCL tie.
They have a near-telepathic understanding as they've shown on numerous occasions this season, with Neymar's assist for Mbappe's opener against Bayern being an apt example of their chemistry on the pitch. Mbappe has eight goals to his name while Neymar has six, the highest and second-highest tallies respectively among active players in the competition.
PSG's trident of Mbappe, Neymar, and Di Maria complement each other perfectly and could prove to be a handful for any defence in the world, including one as good as Manchester City's.