Ghana’s players have promised that they will not boycott Thursday’s crucial World Cup group game against Portugal after an extraordinary row over appearance money that has forced the country’s president to intervene. The issue has cast a huge shadow over their preparations and had still to be resolved when they trained at the Estádio Nacional on Wednesday night.

James Appiah, the Ghana coach, said that an agreement was close when he spoke at his pre-match press conference, but he also admitted that he had suffered sleepless nights dealing with the problem and expressed his dismay that his players had not been paid long before.

It appears that each member of Ghana’s squad is entitled to a significant five-figure sum for taking part in the World Cup – an appearance bonus that was agreed before arriving in Brazil. However, when that money failed to arrive by the start of this week, the players decided to take a stand. It is understood that they refused to train on Tuesday.

The Ghana Football Federation issued a statement 24 hours later saying that the President, John Dramani Mahama, “personally spoke to the players” to assure them they would be remunerated. The situation is complicated further by the fact that Ghana’s players have demanded to be paid in cash. Incredibly, there are suggestions that a plane will fly in from Ghana to Brasília with $3m (£1.76m) on board.

For Appiah, the stand-off could not have happened at a worse time. “Every coach wouldn’t love to be in this situation where players are requesting monies, considering the fact you are playing a very important game,” he said. “For the past two days I’ve had sleepless nights, I can’t even close my eyes. These things are normally sorted out before the competition, you can’t keep telling the players the money will come. Unfortunately, I’ve found myself in that situation, trying to cope with it. The good thing is the president of the country will step in.”

Ghana will receive a minimum of $8m from Fifa even if they are knocked out at the group stage – they need to beat Portugal to have any chance of reaching the last 16 – but, as Appiah explained, that sum will not be transferred until the World Cup is over. “It’s always difficult,” he said. “Fifa does not pay before the players arrive for the competition, Fifa pays after. The government or the FA has to find money to pay and later get it back off Fifa. Once there is a delay in getting it from the government or FA it becomes a problem.”

Appiah would not disclose how much exactly the Ghana squad were demanding – “The players would kill me if I revealed it,” he said, laughing – but he defended their stance. “It’s not about being paid reward for anything, it’s got to do with an appearance fee, which I think every country pays its players, not just Ghana. It’s a right.”

Asked why the players could not have the money transferred electronically, Appiah said: “The practice in Ghana has always been to pay players in cash. Some players have not got accounts in Ghana. The system in Africa is totally different to Europe. You need to consider those factors. I’m not saying that it is the best way. But we are coming from different areas and you need to understand how it works.”

Christian Atsu, the Chelsea winger, insisted that there was no prospect of the players refusing to take to the field against Portugal if the money failed to arrive. “We are in the biggest tournament in the world now, if we don’t get the money, we’ll just put everything behind us because the whole world is watching us. We are not going to say: ‘Because of the money we’re not going to play’,” he said.

“We had these issues but now we had a meeting and our captain [Asamoah Gyan] spoke with us. We respect him every much. Now we’re all focused on the game, a game that is very important for all Ghanians, also for us, the players. It will be bad if we lose the game, because I think people will think it’s because of the money. So we have no option but to do our country proud.”

Asked where the players proposed to keep the cash, Atsu smiled and replied: “That’s a difficult question for me. Of course we will keep it in our bags. We just lock them. We will transfer all the money into our account.”