The 2021-22 UEFA Champions League journey continues for PSG as they take on RB Leipzig on Matchday 4 of Group A. Following a great transfer window, Paris Saint-Germain aim to finally get their hands on the coveted continental trophy this campaign.

That's why they built one of the mightiest squads of all time by landing Lionel Messi, Gianluigi Donnarumma, Georginio Wijnaldum, Achraf Hakimi, and Sergio Ramos, although he has yet to make his debut and his situation looks really uncertain.

By adding those names to a roster that already included the likes of Neymar, Kylian Mbappe, Marquinhos, Keylor Navas, and Marco Verratti, Paris automatically became favorites to win the UCL trophy once and for all. However, their performances left much to be desired, and Messi suffered another setback on his tough start to life in Paris.

Why is Lionel Messi not playing for PSG vs. Leipzig in the Champions League?

It's quite clear that Messi has been unable to perform at his best in the French capital so far. But the few good moments he lived in Paris until now were in the continental tournament, so his absence for this match is a huge blow.

Lionel Messi was ruled out of PSG's clash with Leipzig due to a hamstring injury that has forced him off their last match against Lille. "Leo Messi has discomfort in his left hamstring and pain in his knee following a contusion," the club's stament read as the Argentine star didn't travel to Germany with the squad.

Messi has three goals in the Champions League this season, having scored to Manchester City and adding a brace against Leipzig on Matchday 3. In the Ligue 1, however, he has yet to score a goal after five appearances. Injuries caught up with him during his first months in PSG, something that apparently has people at the club quite unhappy.