World Cup footballers often face an unexpected hurdle as they try to cope with the intense scrutiny and pressure of the game’s biggest showpiece — it can be boring… really, really boring.

In the periods between matches, players are isolated at remote training camps in the countryside, surrounded by tight security and high walls to discourage prying eyes.

Contact with family is usually strictly controlled or non-existent, leaving the young men cooped up for weeks, rubbing shoulders with the same teammates day after day.

Australia coach Bert van Marwijk admits it can be a recipe for disaster if cabin fever takes hold, causing factionalism or infighting among the squad.

In 2010, the Dutchman managed to unite the notoriously fractious Netherlands enough to reach the World Cup final, despite the presence of several big personalities who each wanted to be pack leader.

“I told the Holland players in 2010, we will get bored. But we have to win the World Cup, we have to work together,” he told Sydney’s Daily Telegraph.

Van Marwijk said a major part of maintaining harmony was making players understand they had to respect one another, even if they might never be friends.

“Everyday a few small things happen and those things are very important for the atmosphere in the whole group,” he said.

“You cannot find it in any book, it’s the way you lead the group, manage the group.”

– Club v country –

Club rivalries can emerge, such as those which in the past have created splits in the Spain team between Barcelona and Real Madrid players.

Thomas Mueller admitted Germany divided into Bayern Munich and Borussia Dortmund blocs at Euro 2012 but denied a similar schism was behind their opening-round loss to Mexico at the current tournament in Russia.

“We didn’t have the best kind of chemistry back then, but it is totally different today,” he insisted.

Sometimes players fed up with their camp routine take desperate measures.

Former England forward Jermain Defoe was so mind-numbingly bored at England’s 2010 base in South Africa that he watched strike partner Wayne Rooney’s entire wedding video from beginning to end.

Years later, details of Rooney’s nuptials remained seared into his brain.

“Wayne had something like a flash mob, the waiters were singing, dancing, if I can remember,” he said.

“Yeah, you do get bored, but all the teams get bored.”

England seem to have learned their lesson and have tried to make their current camp at Repino, outside Saint Petersburg, a relaxed, fun environment.

– Climbing the walls –

England’s siege mentality of the past has eased as Gareth Southgate’s men race inflatable unicorns in the pool and engage in darts competitions with the media.

Iceland are taking a similar approach, flying in a group of comedians to give the players a boost.

“The team is here for the long haul and we are in it together. It is important to keep us all fresh and do something entirely different every now and then,” said team spokesman Omar Smarason.

World Cup boredom can lead to players literally climbing the walls to get away from camp and blow off some steam, and it’s not a new phenomenon.

Former Mexico goalkeeper Antonio “Tota” Carbajal recalled how at the 1966 tournament in England two players sneaked away to a bar — with coach Ignacio Trelles hot on their heels to drag them back.

Carbajal, a veteran of five World Cups, argued players behaving badly was not necessarily a bad thing.

“These things unite the team,” the 89-year-old told AFP.

A laid-back approach certainly worked for the late Denmark coach Richard Moller Nielsen, who gave his players unprecedented freedom — including visits to fast-food outlets — during their victorious run at Euro 92.

“Perhaps it would be a good idea if we drink a beer and drive past McDonald’s now and then. I will suggest that to the coach,” current Denmark defender Jannik Vestergaard suggested, perhaps a touch wistfully.

Neymar has now “totally recovered” from the foot injury that required surgery and saw him miss the end of the club season, Brazil’s team doctor said on Saturday.

However, winger Douglas Costa will miss the side’s final World Cup Group E outing against Serbia on Wednesday.

“I would like everyone to understand Neymar’s situation, and that he no longer has any problem with his right foot,” Rodrigo Lasmar told journalists at Brazil’s World Cup training base in Sochi.

“He has totally recovered but he is still building up his rhythm and his confidence. He is feeling better with every game.”

Lasmar sought to reassure Brazilian media worried about Neymar’s fitness after he limped out of a training session with a sore right ankle following Brazil’s opening 1-1 draw with Switzerland last weekend.

That raised fears, particularly as it was just above the foot that he fractured playing for Paris Saint-Germain in late February, before undergoing surgery.

He did not start a game again until Brazil’s final World Cup warm-up friendly in Austria two weeks ago, and he took a further knock on the left ankle in Friday’s 2-0 win over Costa Rica.

Despite that, he was still on the pitch to score his team’s late second goal in Saint Petersburg.

“The problem with his left ankle is not something that worries us. Tomorrow he will train normally with the rest of the players,” said Lasmar.

The Brazilian camp were unhappy with the treatment Neymar received in the Swiss game, when statistics showed he was fouled 10 times. And Lasmar reiterated those complaints.

“Opponents commit fouls to try to stop him,” he said. “We expect the refereeing to contain that. I am not specifically talking about the risk to Neymar. Fouls can happen.”

Juventus winger Costa will not be able to face Serbia in Moscow due to a thigh problem suffered after coming on as a half-time substitute against Costa Rica.

Philippe Coutinho and Neymar both scored in stoppage time for Brazil, who now need only draw with Serbia to secure a place in the last 16.