The Brazil star injured his right foot when Strasbourg midfielder Moataz Zemzemi attempted to tackle him three times before referee Johan Hamel awarded a free-kick.
Neymar was angered by the rough treatment meted out by Zemzemi and got a form of revenge when he flicked the ball over the Strasbourg man's head before firing wide from the resultant set-piece.
However, Neymar left the pitch shortly after to receive treatment and, though he came back on, appeared emotional as he made his way down the tunnel with Moussa Diaby replacing him in the 62nd minute.
Edinson Cavani's early strike had given PSG the lead in the last 32 match, and despite Neymar's absence, the French giants wrapped up the contest through Angel Di Maria in the 80th minute.
Speaking to Eurosport after the match, PSG boss Thomas Tuchel expressed his concern for the world's most expensive footballer, saying: "No, I did not talk to Neymar because he's in the hospital. Yes, I'm worried.
"It's always complicated. It's the same foot and the same metatarsal [as the injury suffered in early 2018]."
The club themselves released a statement shortly after, which reads: "Initial examinations have revealed a painful recurrence of his injury to the fifth metatarsal of his right foot.
"The treatment of this injury will depend on how it evolves over the next few days.
"All options can be envisaged at this time."
Marco Verratti suffered what Tuchel called a "very, very serious" injury during Saturday's win over Guingamp, and with the first leg at Old Trafford only three weeks away on February 12, the former Borussia Dortmund boss will be praying for good news on both players.
Rumours have been swirling around Neymar's future recently with the attacker linked with a return to Barcelona as stories continue to persist about his unhappiness in the French capital.
However the Catalan club rejected reports they were contacted by the 26-year-old's father and agent Neymar Santos Sr.
Neymar moved from Barca to PSG in the summer of 2017 in a world-record €222 million deal.
Neymar was also forced to defend himself from criticism aired by Brazilian legend Pele over the 'things he does besides playing football'.
They are next in action against Rennes on Sunday as they look to maintain their unbeaten league campaign thus far.