Barcelona doctor Richard Pruna has admitted that the club's new signing Neymar "is lacking the odd little kilo" ahead of the new season.

The 21-year-old, who joined the Catalan outfit on a five-year contract from Santos this summer, weighs just 64.5 kilograms.

"We gave him a very speedy checkup and his weight was one of the pieces of information," Barca Pruna told reporters at a press conference.

"The first impression is that his weight of 64.5 kilograms is on the low side and maybe he is lacking the odd little kilo but I cannot say exactly how much.

"As the season progresses we will get to know the player and we are constantly gathering information. That way we can determine his ideal weight."

Neymar is currently competing in the Confederations Cup for Brazil.