The UEFA Champions League trophy is displayed at Halic Congress Center in Istanbul, Turkey, August 26, 2021. /CFP
The line-up for the UEFA Champions League group stage was revealed on Thursday with six play-off winners joining the 26 direct entrants.
Lionel Messi's new club Paris St-Germain (PSG) will play Manchester City, managed by the Argentinian's former Barcelona coach Pep Guardiola, after the two were drawn together in Group A.
Messi joined the French club, which will also face Bundesliga side RB Leipzig and Belgium's Brugge, from Barcelona this month after the Spanish side were unable to afford a new contract for the forward.
The draw pits two of European football's wealthiest teams against each other once again as they both seek their first Champions League title, with City beating the French side 4-1 on aggregate in last season's semis.
City went on to lose the final to Premier League rivals Chelsea, who were drawn in Group H against Juventus, Zenit St Petersburg and Malmo.
City have yet to lose to PSG in the Champions League but Messi has also scored more goals against them – six in six games – than any other side in the competition.
"After the Porto, Liverpool, Atletico Madrid group, our group is probably the second most difficult one," said City's director of football Txiki Begiristain.
"Some of the big names in football are going to be out. That is the magnitude of this competition."
Spanish champions Atletico Madrid and Liverpool were drawn in Group B with former winners Porto and AC Milan, while Real Madrid play Inter Milan, Shakhtar Donetsk and Moldovan debutants Sheriff Tiraspol in Group D.
Six-time winners Liverpool and manager Juergen Klopp will at least have fond memories of Atletico's Metropolitano stadium in Madrid after winning the 2019 title there against Tottenham Hotspur.
"I laughed, to be honest, pretty loud because it is a tough group obviously," Klopp told Liverpoolfc.com.
"We played. I don't know how often, already against Porto, so they will be waiting for us. We have obviously a little bit of (an) open bill with Atletico, and AC Milan, a historical one obviously. I think our supporters should be looking forward to it – we do, for sure," Klopp added.
The group stage draw results for the 2021/22 UEFA Champions League are displayed on the screen during the draw ceremony at Halic Congress Center in Istanbul, Turkey, August 26, 2021. /CFP
Group A:
Manchester City (England)
Paris Saint-Germain (France)
RB Leipzig (Germany)
Club Brugge (Belgium)
Group B:
Atletico Madrid (Spain)
Liverpool (England)
Porto (Portugal)
AC Milan (Italy)
Group C:
Sporting CP (Portugal)
Borussia Dortmund (Germany)
Ajax (Netherlands)
Besiktas (Turkey)
Group D:
Inter Milan (Italy)
Real Madrid (Spain)
Shakhtar Donetsk (Ukraine)
Sheriff Tiraspol (Moldova)
Group E:
Bayern Munich (Germany)
Barcelona (Spain)
Benfica (Portugal)
Dynamo Kiev (Ukraine)
Group F:
Villarreal (Spain)
Manchester United (England)
Atalanta (Italy)
Young Boys (Switzerland)
Group G:
Lille (France)
Sevilla (Spain)
Salzburg (Austria)
Wolfsburg (Germany)
Group H:
Chelsea (England)
Juventus (Italy)
Zenit St Petersburg (Russia)
Malmo (Sweden)
(With input from Reuters)