It is second versus second-from-bottom at the Parc des Princes as PSG, unbeaten in 13 games in all competitions, take on a Lens side who are winless in eight.
This would be the perfect opportunity for PSG manager Laurent Blanc to rest players ahead of their trip to London on Wednesday, but injuries and the risk of slipping up in the title race may force him to go with a strong team.
With the scores locked at 1-1 from the first leg in Paris two weeks ago, the French champions may have to become the first side to win at Stamford Bridge this season to progress to the quarter-finals of the competition.
Blanc may be thankful then that it is the less-threatening opposition of Lens, rather than Monaco, who await his side this weekend.
PSG recorded their 11th Ligue 1 draw of the campaign against the principality outfit on Monday, to cut the gap on league leaders Lyon to a single point, before beating them 2-0 to reach the last four of the Coupe de France.
Salvatore Sirigu should replace Nicolas Douchez in the only expected change to the Parisians' cup side, although Maxwell could also return in defence to give one of their Brazilians a rest ahead of the Chelsea clash.
Star striker Zlatan Ibrahimovic is likely to be given the day off as he manages the heel problem that has hampered his season. Yohan Cabaye, Thiago Motta and Lucas Moura are all missing for both of PSG's matches this week.
Lens have picked up just three draws in eight games since the resumption of the French season after the winter break and have fallen nine points adrift of safety in their battle to avoid relegation straight back to the second tier.
Manager Antoine Kombouare could make just the one change to the side that went down 1-0 to Rennes last weekend, with Alharbi El Jadeyaoui pushing for a start in midfield at the expense of Wylan Cyprien.
Jean-Philippe Gbamin and Jerome Le Moigne, both of whom were sent off as Lens lost the eventful reverse fixture 3-1 in October, could join him in the centre of the park as the visitors seek a first win over PSG since 2006.
Form in Ligue 1: WWDDWD
Form in all competitions: WDDWDW
Possible starting lineup: Sirigu; Digne, Silva, Marquinhos, Maxwell; Rabiot, Matuidi, Verratti; Pastore, Lavezzi, Cavani
Form in Ligue 1: DDDLLL
Possible starting lineup: Riou; Kantari, Landre, Baal, Gbamin; Le Moigne, Valdivia, El Jadeyaoui; Touzghar, Chavarria, Guillaume
Sports Mole says: 1-0