The chaos at the Lisbon club, where staff have been attacked and whose president’s outbursts have sparked player unrest, has been an unwelcome distraction for Portugal

“Spoiled kids, let’s resolve this then …” wrote the Sporting president, Bruno de Carvalho, on his personal Facebook account at the start of April. Two months on, after a period in which 19 players have been suspended and a group of hooded men forced their way into the club’s training ground armed with sticks after defeat in the final league match of the season, it’s fair to say things have not worked out quite the way the man some have labelled the “Donald Trump of football” would have planned.

Portugal World Cup 2018 team guide: tactics, key players and expert predictions Read more

While Spain have problems of their own as the Iberian nations prepare to meet in their opening match at th e 2018 World Cup, the fallout from the Sporting soap opera has marred the buildup to the tournament for the reigning European champions. On Monday Gelson Martins, William Carvalho and Bruno Fernandes joined the goalkeeper Rui Patrício in cancelling their contracts, citing “valid motives” for their decision. The Netherlands international Bas Dost, who was one of the players injured in the training ground attack, has also indicated his desire to leave one of Portugal’s most famous clubs, even accusing the president of perpetrating of “psychological violence” towards him, with the law courts now set to rule on the case.

“It’s a big mess,” admits Nuno Travassos of the Portuguese website maisfutebol.pt. “He was seen as the saviour and even now the club is split in two. There are still many people who support De Carvalho and want him to stay, even after all this controversy. He has always liked to speak about the team’s performances and uses social media a lot. That’s why some of the newspapers have made the comparison with Trump.”

Surprisingly elected in March 2013, De Carvalho has proven to be a popular choice among supporters for his frequent attacks on the Portuguese football establishment, including accusing their Lisbon rivals Benfica of offering gifts to referees.

He has even been known to sit on the bench during matches – “creating a presence” as he described it – and also regularly texted his players after matches to make plain his dissatisfaction with their performances. But despite the controversial appointment of Jorge Jesus as manager after he left Benfica, Sporting’s season unravelled after the 2-0 defeat to Atlético Madrid in the first leg of their Europa League tie that prompted De Carvalho’s Facebook post.

Having previously promised to stay away from social media after one outburst in 2015, the president’s accusation that members of his team had committed “grotesque mistakes” understandably did not go down well. Nineteen players subsequently posted their own statement on Facebook noting their “displeasure with the public declarations of our president” – a move that prompted De Carvalho to threaten them with suspension.

Facebook Twitter Pinterest The prolific social media postings of Sporting’s president, Bruno de Carvalho, have prompted comparisons with Donald Trump. Photograph: Pedro Nunes/Reuters

Perhaps unsurprisingly, the denouement of the season was a disaster as Sporting finished third in the table, failing to qualify for the Champions League, before the damaging defeat to the minnows Aves in the Portuguese Cup final, who have been a top-flight side for only three seasons. Having already complained about fans being allowed access to the private car park at the club’s training ground, the attack on Dost, Jesus and several other members of staff a few days before the final proved to be the final straw.

Paulo Futre picks his all-time Portugal XI Read more

“The environment became awful,” says Travassos. “The players said in their resignation letters that the president and the board are responsible for this situation because they contributed to this bad environment and didn’t assure the security conditions of the team. That’s why they say they have reason to leave.”

Patrício, the 30-year-old goalkeeper who has won nearly 70 caps, was the first to tender his request to terminate his contract after a proposed €18m transfer to Wolves was vetoed by De Carvalho at the last minute, while the winger Martins and midfielders Carvalho and Fernandes have also been linked with moves to the Premier League in recent days. Whether they get their wish remains to be seen, with De Carvalho having since offered to resign if all the players who want to leave reverse their decision, although the Portugal coach, Fernando Santos, may fear the damage has already been done.

“Some of them are experienced players but obviously it’s something that they would have wanted to avoid,” says Travassos. “Usually the only thing we talk about in press conferences is Ronaldo, Ronaldo, Ronaldo but this time, there is more about Sporting.”

World Cup Fiver: sign up and get our daily football email.

But with a squad that contains 13 of the 23 players who helped win the country’s first major silverware at Euro 2016, Portugal supporters have every reason to feel quietly confident of their chances. A comparison with the 1986 World Cup – when a talented squad went home bottom of their group after falling out with the Portuguese FA over bonuses – is tempting, especially given the presence of Morocco, to whom they lost 3-1 in their final match 32 years ago after defeating England, in their group. Yet with top-level players throughout the squad led by Cristiano Ronaldo in what is likely to be his last appearance at a World Cup, anyone who writes off Santos’s side does so at their peril.

“I don’t think this has changed anything among the fans,” says Travassos. “It’s a bad situation of course but expectations are still the same. The players will be focused and if there is a problem, the coach has others to replace them. We don’t have the options of many countries but we have very good quality.”