UEFA have opened disciplinary proceedings on Neymar after his foul-mouthed outburst about referees following Paris Saint-Germain's controversial Champions League exit to Manchester United last week, the governing body announced on Wednesday.

Injured Brazil forward Neymar launched into a diatribe against the match officials shortly after the defeat on Instagram.
He watched on incredulous from the sidelines at the Parc des Princes as United were awarded a stoppage-time penalty for a debatable handball via the video assistant referee (VAR) system.

Marcus Rashford crashed home the spot-kick to give the Premier League side a last-gasp 3-1 win that saw them into the quarter-finals on away goals.

"It's a disgrace. They get four guys who don't understand football to watch a slow-motion replay in front of the TV ... Go fuck yourselves!" Neymar wrote in Portuguese on the social media website.

The 27-year-old was so reportedly enraged he had to be restrained by PSG staff to stop him entering their dressing room.

"A disciplinary investigation has been initiated ... in connection with the comments made on social media by the Paris Saint-Germain player Neymar following the above-mentioned match," UEFA said in a statement.

If found guilty Neymar risks punishment ranging from a fine to suspension.