The relegation-threatened hosts will move out of the bottom two positions with a win over Luis Enrique's men, who could be crowned champions if results elsewhere go their way.
Match preview
Lorient should have hosted PSG before Enrique's men travelled to Barcelona for their Champions League quarter-final second-leg clash, but the game was moved to aid the Ligue 1 giants' preparation for continental football.
Regis Le Bris hopes his team catch the league-leading outfit distracted by the imminent European semi-final first-leg against Borussia Dortmund, keen to boost survival hopes in Brittany.
However, a wretched run of results in the competition leave the home support unsure of Wednesday's result, having lost three games on the trot without scoring against Brest (1-0), Montpellier (2-0) and Nice (3-0).
Digging deeper, Le Bris' troops losing five of their last seven matches in the competition does not bode well for a side hoping to avoid relegation from the top flight.
Having not won a Ligue 1 game since March 3, the club whose last victory in Brittany came on February 11 — a 2-0 success over Reims — face an uphill task against the champions-elect.
Enrique made several changes to the side that thumped Barcelona 4-1, including leaving out Kylian Mbappe for the entirety of Lyon's visit to Paris on Sunday.
It was not costly for the Parisians, with Goncalo Ramos notching a brace and Marco Asensio setting up one in another 4-1 triumph for the hosts, who dispatched a side that were undefeated since March 3.
A 12th league crown could be claimed on Wednesday, even if that outcome is contingent on PSG defeating Lorient at Stade du Moustoir and Monaco failing to secure maximum points in the later fixture against Lille.
As 11 points separate the clubs, with both having five matches to play, it is only a matter of time before Les Parisiens notch another topflight title.
The visitors have reason to be optimistic heading into Wednesday, having not lost in Ligue 1 since mid-September — a 3-2 defeat to a Terem Moffi-inspired Nice — while claiming five wins in six away games (one draw), keeping four clean sheets in that period.
Lorient Ligue 1 form:
W
L
D
L
L
L
Paris Saint-Germain Ligue 1 form:
D
D
W
W
D
W
Paris Saint-Germain form (all competitions):
W
W
D
L
W
W
Team News
Quentin Boisgard (foot) is not expected to play any part on Wednesday, having missed the whole season with his injury.
Laurent Abergel, Bamba Dieng (both calf), Montassar Talbi (shoulder), Bonke Innocent (thigh) and Igor Silva (knee) are not anticipated to feature in mid-week.
Despite sitting out PSG's win over Lyon, Enrique could reinstate Mbappe and Ousmane Dembele to the lineup at Lorient.
Sergio Rico (head) is said to be out until the season concludes, while Presnel Kimpembe (Achilles) and Layvin Kurzawa (back) — the latter has played only eight minutes in Ligue 1 this term — should miss out.
Lorient possible starting lineup:
Mvogo; Mendy, Adjei, Toure; Katseris, Bakayoko, Louza, Le Bris; Ponceau, Kari; Bamba
Paris Saint-Germain possible starting lineup:
Donnarumma; Hakimi, Marquinhos, Skriniar, Hernandez; Ugarte, Vitinha, Zaire-Emery; Dembele, Ramos, Mbappe