Alexander Isak started up front alongside Hugo Ekitiké, who was forced to leave Anfield on a stretcher after half an hour.
The Frenchman was about to take a few steps forward to meet a challenge, but collapsed without close contact with any opponent and landed on one foot.
"It doesn't look very good. We could all see it didn't look good. He left in the second half, so I haven't met him yet. It's tough to lose a game, but losing a player is something we've experienced so many times this season," Liverpool coach Arne Slot told Amazon Prime, according to Sky Sports.
Played one half
For Isak, it was the first time he had started a football match since he broke his fibula and injured his ankle during a league match on December 20. In the past week he had made two short substitute appearances, and Slot surprised many by starting the Swede in the crucial match against PSG.
"It might have been a little surprise, but we needed to score. We signed Isak for a reason. He has been substituted twice before, so for me he was ready for at least 45 minutes," Slot told Viaplay.
Isak didn't get many balls to work with during the half he played. When the second half started, the Swede was substituted.
With barely 20 minutes left to play, Liverpool's hopes of progressing in the Champions League were extinguished.
Frenchman Ousmane Dembélé - who was named the world's best men's player last year - twisted and turned outside the penalty area before definitively securing the reigning champions' place in this year's semi-finals with a long-range strike. In added time, Dembélé also scored to make it 2–0.
Barcelona eliminated
Catalan giants Barcelona faced the same task as Liverpool, away to Atlético Madrid, but after 24 minutes the 0–2 deficit had been erased by goals from Lamine Yamal and Ferran Torres.
After just over half an hour Atlético Madrid were once again in the semi-finals when Ademola Lookman scored the equalizer, a goal that sent Atlético through with a 3–2 aggregate win.
Sweden international Roony Bardghji was brought on in the 89th minute for Barcelona.
Quarterfinals
Wednesday: Arsenal-Sporting Lisbon (1-0), Bayern Munich-Real Madrid (2-1).
Semifinals
Paris Saint-Germain vs Bayern Munich/Real Madrid.
Atletico Madrid vs Arsenal/Sporting Lisbon.
Semi-finals will be played on April 28–29 and May 5–6.
The final will be played on May 30 in Budapest, Hungary.
