Barcelona forward Neymar appeared to confront a Manchester City fan at the full-time whistle of the Champions League clash at the Etihad Stadium.
Neymar was substituted in the 80th minute of the last-16 first-leg game, which Barca won 2-1, and footage posted on YouTube shows the 23-year-old apparently remonstrating with a section of City's support from the visiting dugout.
Once the full-time whistle was blown, the Brazilian then walked to the pitch side and looked to be in a heated discussion with one City supporter in particular, with stewards intervening to defuse the situation.
Luis Suarez scored twice on his return to England although City striker Sergio Aguero narrowed the deficit before Lionel Messi missed an injury-time penalty. Watch highlights on our Champions League site.
Pele is among many high-profile football stars including Ruud van Nistelrooy, and Gilberto Silva who have sent their support to Neymar after the Brazil attacker's World Cup was ended by injury.
Fifa's disciplinary committee is to analyse the incident in yesterday's World Cup quarter-final which saw Brazil striker Neymar suffer a broken verterbrae.
Colombia defender Zuniga challenged the Brazil star from behind in the closing stages of the game causing a back injury, which has now ruled out the Barcelona forward out of the tournament.
FIFA head of media Delia Fischer said: "The disciplinary committee is analysing the matter. The spirit of fair play is very important and we want to avoid difficult things on the field of play."
Costa Rica coach Jorge Luis Pinto is worried Arjen Robben will try to give Holland an advantage by diving in Saturday night's World Cup quarter-final in Salvador at 9pm.
Earlier in the day at 5pm, Argentina will be hoping Lionel Messi is proves to be the difference, while Belgium coach Marc Wilmots has called on his players to make history to reach their first semi-finals since 1986
Video footage has been captured showing Neymar being admitted to hospital after it was announced he will not play again in World Cup 2014. The host's team doctor revealed the Brazil striker has fractured vertebrae.
Brazil forward Neymar has been ruled out of the World Cup after fracturing his vertebrae in the closing stages of the 2-1 quarter-final win over Colombia on Friday, his team said.
"It's not serious in the sense that it doesn't need surgery, but he'll need to immobilise it to recover," team doctor Rodrigo Lasmar said after the player had been taken to hospital.
"Unfortunately, he's not going to be able to play," he said, adding he expected the recovery period to take at least a few weeks."
Brazil manager Scolari claimed that striker Neymar has been "hunted" during the World Cup.
Brazil striker Neymar ruled out of World Cup with fractured vertebrae says team doctor.
Brazilian football star Neymar scored a spectacular goal in the Confederations Cup last night after saying he had been inspired by the protests in his country's two biggest cities.
Before yesterday's match against Mexico, Neymar surprisingly spoke up in favour of the protestors, an unusual move for footballers who usually steer clear of politics.
"I'm Brazilian and I love my country. I have a family and friends who live in Brazil. For that reason, I want a Brazil which is more just, safer, healthier and more honest, which is the obligation of the government," he said on Facebook.
"The only way I can represent and defend Brazil is on the pitch, playing football. From now on, I will enter the field inspired by this movement."