Watch: Neymar storms out of training after bust-up with Semedo

Neymar had to be restrained by Barcelona teammate Sergio Busquets after nearly coming to blows with summer signing Nelson Semedo during a pre-season training session Thursday.

The Brazilian kicked a ball in frustration and threw off his bib before storming off the pitch in scenes that cast yet more doubt on his future with the Catalan giant.

Various reports suggest Paris Saint-Germain is prepared to trigger Neymar's €222-million release clause and offer mammoth wages to the 25-year-old.

Related - Report: PSG growing confident over Neymar, Sanchez moves

Rumours of a world-record switch plateaued over the past week, as Neymar scored three times in pre-season fixtures against Juventus and Manchester United.

But the latest development appears to show the degree of tension in Barcelona's camp.

Neymar made matters worse by cancelling a commercial appearance with a travel agency in China. According to Reuters, Ctrip said on its official Weibo account that Neymar couldn't attend because he is "busy with transfer business."

He was scheduled to fly out separately from his teammates to take part in the event in Shanghai on Monday.