Neymar limped off with an apparent right foot injury after one hour of Paris Saint-Germain's 2-0 Coupe de France win against Strasbourg on Wednesday.
His manager Thomas Tuchel said he was taken to hospital for further evaluation, with the club later confirming he'd reinjured the fifth-metatarsal in his right foot that required surgery ahead of the 2018 World Cup.
The Brazil forward had just received the ball on the left when he raised his hand to seemingly signal to Tuchel that he was in pain, and looked to be in tears as he left the field at Parc des Princes.
Neymar limped heavily as he walked to the dressing room, consoled by a PSG staff member, and looked upset as he wiped his face with his right arm.
"Initial examinations have revealed a painful recurrence of his injury to the fifth metatarsal of his right foot," the club said in a statement. The treatment of this injury will depend on how it evolves over the next few days. All options can be envisaged at this time."
It was unclear how Neymar sustained his latest injury, but he had been on the receiving end of a heavy tackle from midfielder Anthony Goncalves earlier in the match.
Television images then later showed Neymar rolling off his sock and pointing to the side of his right foot, which he also fractured nearly exactly one year ago while playing in the Ligue 1 against Marseille.
"Neymar is worried, because it's the same foot, the right foot, in the same area," Tuchel said. "There's no news for the moment, he's gone to hospital. I need to wait for the doctor to give me news about Ney.
"If Neymar asks to come off, it is always something complicated."
Last February, Neymar cracked the metatarsal, and he underwent surgery back home in Brazil. Although he recovered in time for the World Cup last summer, he was not at his best in Russia.
Tuchel said Neymar was not protected enough on the pitch.
"The referee didn't whistle on one occasion, then two, then three and after that he ended up twisting his foot," Tuchel said.
PSG captain Thiago Silva told Eurosport: "Neymar is a smart guy. I think that he went off before he was totally hurt. We will see. The doctor will update us. I hope that it is nothing serious. We will see if he was crying or not when he came off. If he was crying, then it is because something is up."
But interviewed after the match by broadcaster Eurosport, Goncalves expressed no sympathy for Neymar and even suggested the injury is a direct result of how he plays.
"It's his style. But if you play like that don't complain if you take some knocks after," Goncalves said. "He's a great player, and I respect the player he is, but we're not here so he has fun at our expense. We're not here to make him look good."
Goncalves suggested Neymar, who has a tendency to showboat and even toy with opposing players with his skillful trickery, lacks humility.
"If he wants to have fun, we'll respond with the weapons we have. We have a jersey to defend. We're not here for a laugh," Goncalves said. "He can amuse himself, that's his style and I think people come to watch that. But he shouldn't come and moan about it afterward [and] he likes to do that. It's part of his arsenal and we respond in our way."
Strasbourg coach Thierry Laurey also said Neymar's attitude is all wrong.
"Sometimes when you've gone too far, you have to face up to it," Laurey said. "I can understand my players having enough of players who are looking to tease them, mock them. It's right that after a while it also catches up with him. I'm all for protecting players, but there are limits. When you make a pass that comes off your back, you're mocking a bit."
Strasbourg defender Pablo Martinez added: "Of course he's a marvelous player, but because of his attitude he's not someone I like on the pitch. Apart from teasing you, he talks to you badly."
Tuchel now faces an anxious wait as the extent of Neymar's injury is determined.
PSG travel to play Manchester United in the first leg of their Champions League last-16 match on Feb. 12 and is already sweating on the fitness of key midfielder Marco Verratti after he sprained his ankle last weekend.
Two months ago, Neymar was substituted with a groin injury during the first half of Brazil's friendly against Cameroon on Nov. 20.
ESPN's Jonathan Johnson and the Associated Press contributed to this report.