The legendary No.10 is a massive fan of the Brazilian superstar but fears that his new employers might try to persuade him to bulk upBarcelona will try to turn Neymar into "a bodybuilder".
There has already been great media focus on the Brazilian's weight since his arrival at Camp Nou, with the 21-year-old having lost seven kilograms after an operation to have his tonsils removed.
Now Maradona is concerned that the Blaugrana's coaching and medical teams might decide that their star summer signing needs to bulk up.
"Neymar delights me," the legendary Argentine told reporters. "He is a player that should be noted.
"He knows what to do with himself and that he does not need to be a bodybuilder. I hope they [Barcelona] don't do that with him. He just has to play football."
Despite his admiration of Neymar's considerable talent, Maradona believes that Argentina will win next year's World Cup on account of another Barcelona player, Lionel Messi.
"What Brazil showed in the Confederations Cup is that the team, with great concentration, is unbeatable," he conceded. "But I'm putting my money on Argentina because of the great form of Messi."
Argentina has not won the World Cup since Diego Maradona inspired his country to victory in Mexico in 1986.