Can PSG win a third straight Champions League without injured Kvaratskhelia?

As Paris Saint-Germain head to Spain to face Villarreal on Tuesday, the French club's quest to win a third consecutive Champions League title is under threat as injuries to key players raise doubts about the strength of their squad for another tilt at European glory.

PSG's thrilling 4-2 win two weeks ago against Barcelona was overshadowed by the sight of Khvicha Kvaratskhelia having to be helped off injured in the second half.

The Georgian was probably the best player in last season's Champions League knockout rounds, with seven goals and four assists in eight games up to and including the final against Arsenal.

But the rupture to the anterior cruciate ligament in his right knee which the 25-year-old suffered in the win over Barcelona means he is unlikely to return this season.

That is a hammer blow for PSG, who have become Europe's outstanding club side since Kvaratskhelia joined from Napoli in January last year.

Luis Enrique's team began this season's league phase with three wins from three and are well set to reach the knockout stage, but PSG must now be mulling whether to sign a replacement for Kvaratskhelia in the January transfer window.

"Not especially. No injury means we need to sign a new player. None," Luis Enrique said when asked if PSG now needed to go shopping.

"I already said at the start of the season that our team could stay the same, even with two or three injuries. That said, we are always open to the possibility of new players. But not just because we have injuries."