PARIS -- Ousmane Dembélé's injury problems resurfaced during Paris Saint-Germain's 4-2 Champions League win over Barcelona when the reigning Ballon d'Or winner limped off after just 20 minutes of the Champions League tie.

Minutes later, Barcelona were forced to substitute Dani Olmo after the Spain attacker picked up an apparent injury of his own. Fermín López came on in the 27th minute as Olmo left the field in obvious discomfort.

The injury issues for PSG continued in the second half when another star player, Khvicha Kvaratskhelia, was helped from the field by two members of the medical team after a collision with Barcelona's Xavi Espart saw him fly through the air and land hard. Kvaratskhelia appeared to tweak his knee in the encounter and was unable to walk as he left the field.

PSG midfielder Marquinhos was also injured during the same sequence and came off at the same time as Kvaratskhelia, who was replaced by Maghnes Akliouche. The Brazil international left the field under his own power.

"I am not the doctor. I am the coach," PSG manager Luis Enrique said after the game. "The three injuries is the worst part of the game today. We will have to wait for the tests tomorrow. They are three very important players, so it's really bad news, of course, but that's football."

The injuries did not keep the world's top two sides from putting on the kind of show that was expected going into this clash of European heavyweights. PSG twice pulled ahead only for Barcelona to level on both occasions before Vitinha and Fabián Ruiz scored in the game's final 10 minutes to put it away for the hosts.

"It is because of moments like this that Luis Enrique rested some of our players, but unfortunately the thing we feared later happened," Ruiz said after the game. "We lost Ousmane Dembélé just 19 minutes into the game, then both Marquinhos and Khvicha Kvaratskhelia got injured almost the [same] minute.

"[Kvara's] injury got me scared because the way he fell got me worried. He couldn't walk out of the pitch on his own. I just hope it's not something serious."

The loss was Barcelona's first of the season in all competitions, and after the game manager Hansi Flick said the injured Olmo was very disappointed to have left the match. "We don't yet know how big the injury is, we have to wait and see," Flick added.

Dembélé, 29, endured an injury-ravaged six-year spell at Barcelona before moving to PSG in 2023, and the France forward has largely overcome his fitness problems at the Parc des Princes.

But the former Borussia Dortmund player spent time on the sideline last season and has seen his appearances limited this season by coach Luis Enrique to avoid further problems.

Dembélé's game ended quickly against his former club, however, when he pulled up sharply with what appeared to be a muscular injury as he clutched the back of his left thigh following a run down the left in the 19th minute.

Dembélé, who was replaced by former Barcelona forward Ferran Torres, was able to walk off the pitch, but his fitness will now be a concern for PSG after his latest setback.

PSG have a top-of-the-table showdown with Lyon in Ligue 1 on Sunday.

Information from The Associated Press was used in this report.