But there is far more to it than that which is why Chelsea, enduring one of their worst seasons in years but showing signs of improvement, will visit the runaway Ligue 1 leaders optimistic they can avenge last season's round of 16 defeat.
PSG were on a 16-match winning streak in all competitions before a partly reserve side were held to a goalless draw by visitors Lille in Ligue 1 on Saturday.
Talismanic striker Zlatan Ibrahimovic, key midfielder Thiago Motta and captain and centre back Thiago Silva were all rested and although PSG did not win they still stretched their unbeaten league run to 35 games.
Midfielder Marco Verratti returned after a two-week injury layoff, replacing Javier Pastore at halftime, but manager Laurent Blanc said the Italian would not start against Chelsea.
"It’s too risky. Everything goes faster in a Champions League game. If you play, you risk getting injured again," said Blanc, who is likely to field Adrien Rabiot in midfield alongside Blaise Matuidi and Thiago Motta.
PSG have been knocked out in the quarter-finals of the last three Champions Leagues but hope the addition of Angel Di Maria, who has been an inspiration since he joined from Manchester United last summer, will help them go further this time.
PSG FAVOURITES
Although Chelsea eliminated PSG in the last eight on away goals two seasons ago, the Parisians got their revenge last term when they knocked the London side out.
Chelsea's interim boss Guus Hiddink said last week he thought PSG were favourites, but the outcome is not a foregone conclusion.
Unlike PSG, Chelsea's domestic form has been patchy but it has improved since Hiddink replaced the sacked Jose Mourinho in mid-December.
Saturday's 5-1 win over Newcastle United was their best in the Premier League this term and stretched their unbeaten league run to 10 matches.
However, they are still only 12th in the table, 20 points behind leaders Leicester City.
Saturday's win could prove costly, though, with a hamstring injury making it doubtful John Terry can play.
Hiddink said: "We have just two days to recover and it is something to think about in the future as two days of recovery is not enough."
Terry's fellow central defender Kurt Zouma was ruled out for six months after injuring his anterior cruciate ligament against Manchester United last week.
(Reporting by Julien Pretot; Additional reporting by Mike Collett; editing by Ken Ferris)
