Les Parisiens went down 1-0 to Bayern Munich in the first leg of their Champions League last-16 tie in midweek, while Paulo Fonseca's team eased past Strasbourg 2-0 last weekend.
Match preview
It has apparently taken just six months for the trigger-happy PSG hierarchy to consider parting ways with Galtier, who holds the unwanted honour of overseeing three successive defeats for the French champions for the first time since 2011.
Following a Coupe de France elimination at the hands of Marseille and defeat to Monaco in Ligue 1, a carbon copy of the 2019-20 Champions League final was played out in Paris against Bayern, who gleaned a one-goal advantage in their last-16 tie courtesy of Kingsley Coman's winner.
Not since the days of Antoine Kombouare 11 years ago had PSG suffered a trio of consecutive losses, and should former Lille boss Galtier fail to inspire a turnaround in fortunes over the coming weeks, another swift managerial sacking could be on the cards as the Parisiens' owners continue to dream of Zinedine Zidane.
Despite their ailing form - which has seen them fail to keep a clean sheet in any of their last six matches - the Ligue 1 champions still boast a healthy five-point lead over Marseille at the top of the table, and their unbeaten top-flight streak at home now stands at a whopping 33 matches.
Galtier was at the helm when Lille inflicted PSG's most recent Ligue 1 home defeat in April 2021, and while most of the Frenchman's title-winning crop from that season have moved onto pastures new, Les Dogues still possess an armoury of tools to hurt the wounded champions further.
Few could have ever predicted two New York-born strikers fighting for Golden Boot supremacy in Ligue 1, but Lille's Jonathan David moved ever closer to catching Folarin Balogun at the top of the goalscoring charts with a game-winning brace against Strasbourg last weekend.
The Canada international firstly slotted home a penalty after Edon Zhegrova was felled by Lucas Perrin, and he soon made it 14 for the season after Matz Sels parried Jonathan Bamba's effort into a dangerous area, wrapping up the win for his side before the half-time whistle had blown.
While being a far cry from the team they were during Galtier's reign, Lille's streak of solidity under Paulo Fonseca has Les Dogues firmly in the continental mix as they occupy fifth place in the table, but they have five and six-point gaps to make up to Lens and Monaco respectively.
Dreams of a Champions League return may therefore be slightly far-fetched for Lille, whose patchy form on the road has done them no favours in that regard, as Les Dogues have just three wins under their belt from their last eight Ligue 1 contests away from home.
Galtier's return to the Stade Pierre-Mauroy in December ended with PSG demolishing Lille 7-1, having also prevailed in both contests by an aggregate score of 7-2 last season, and getting one over his former club would be the perfect way for the under-fire Frenchman to get back into the owners' good books.
Paris Saint-Germain Ligue 1 form:
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D
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Paris Saint-Germain form (all competitions):
D
W
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L
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L
Lille Ligue 1 form:
D
W
L
D
W
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Lille form (all competitions):
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D
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Team News
Despite lingering concerns over their fitness, all of Lionel Messi, Neymar and Kylian Mbappe were passed fit for the showdown with Bayern, although the latter only came off the bench after making a rapid comeback from a thigh injury.
With Presnel Kimpembe also making a long-awaited comeback from an Achilles issue, only Renato Sanches and Nordi Mukiele should be absent for the hosts this week. Achraf Hakimi only completed 45 minutes of the clash with Bayern following an injury scare but should be fine to line up here.
Sixteen-year-old Warren Zaire-Emery has been one of the success stories of PSG's season and could earn another start on Sunday, while Kimpembe's return could also give Sergio Ramos a well-earned rest.
Meanwhile, Lille left-back Ismaily is expected to spend another few weeks on the sidelines with a thigh problem, and his absence has seen Timothy Weah operate as an unorthodox defender in recent weeks, but Gabriel Gudmundsson is a more natural solution.
Adam Ounas is also struggling with a thigh injury of his own and will miss out too, while up-and-coming centre-back Leny Yoro missed the win over Strasbourg due to illness and will also need assessing.
In any case, Fonseca should stick with a tried-and-tested formula for the trip to the capital, as 39-year-old Jose Fonte leads the rearguard action against Galtier's famed trifecta.
Paris Saint-Germain possible starting lineup:
Donnarumma; Hakimi, Marquinhos, Kimpembe, Mendes; Zaire-Emery, Verratti, Vitinha; Messi; Mbappe, Neymar
Lille possible starting lineup:
Chevalier; Diakite, Fonte, Djalo, Gudmundsson; Andre, Angel Gomes; Zhegrova, Cabella, Bamba; David
We say: Paris Saint-Germain 2-1 Lille
While PSG have undoubtedly under-performed continentally and domestically in recent weeks, their struggles can be largely attributed to a wealth of injury concerns, which have since subsided.