LUSAIL, Qatar — The giant mural with thousands of faces was certainly an arresting feature for visitors of Qatar’s showpiece stadium in the months leading to the World Cup.

When the buses stopped and the visiting journalists stepped out, they were directed toward a spot near Gate 32. There, in the shadow of the vast golden bowl of the $1 billion Lusail stadium, was an intricate mosaic stretching out and up along a long wall nearly 20 feet high. On it were passport-style photos of men, staring straight ahead.

The mural, a representative of Qatar’s organizing committee said, was a way for the country to pay homage to the army of men who had toiled for years under the scorching desert sun to build the cathedrals to the country’s World Cup ambitions.

But then the World Cup started, and the faces were gone.

Instead, the V.I.P.s and assorted high-rollers who will roll up in expensive cars and luxury vans underneath Gate 32 will only see a wall covered in World Cup logos and slogans. There is no trace of those men, who lived — and sometimes died — to turn a $200 billion nation-building project into reality.

After this article was published, and after multiple requests for comment, Qatar’s Supreme Committee, the organization responsible for building the stadiums, said the change had been made because the arena at Lusail “is currently in tournament mode, with the stadium exterior dressed in FIFA World Cup branding.”

The committee also hinted that the mural, or something like it, might return after the fans have gone. “As part of Lusail Stadium’s legacy plan,” it said in a statement, “the Supreme Committee is finalizing designs to serve as a permanent celebration to recognize the contribution of everyone who contributed to the stadium’s construction.”

Countless thousands of migrant workers from some of the poorest corners of the planet are drawn to the Persian Gulf and other wealthy countries in Asia every year to work on construction projects, as service workers and in other jobs. Human rights groups say thousands of workers who took part in projects related to the 2022 World Cup have died since Qatar secured hosting rights in 2010, a figure that Qatari officials strongly dispute.

In interviews, fans attending the tournament have acknowledged their unease at essentially vacationing in a place built through the hardships of others.

“We wouldn’t be here, the tourists wouldn’t be here, the players on the field would not be here without them,” said Ezequiel Gatti, raising his voice to be heard above the tumult of Argentina’s traveling army after a win over Mexico on Saturday at Lusail. Fernando Lalo, from Buenos Aires, said he was unaware of the mural, but that he hoped something similar might take its place once the tournament is over.

“There should be visibility so people can see, so they can know,” he said.

On Thursday, hours before Brazil’s opening game of the tournament inside Lusail stadium, laborers continued their work nearby, building an apartment complex. Several said they had seen the mural of the workers’ faces before it was obscured but were unaware it had now been removed. But regardless, they said they would not be attending games during the World Cup.

“It’s just crass and disrespectful to put these men in the spotlight when it suits you and then completely obscure their role by painting over it,” said Nicholas McGeehan, the co-director of Fair Square, a human rights group that focuses on the treatment of migrant workers in Qatar.

“I hate to use ‘virtue signaling,’ but it seems appropriate in this instance, highlighting the sacrifice of workers when it suits you from a public relations perspective and removing them from the picture when they cease to be useful.”

Qatar, like most other countries in the Persian Gulf, relies heavily on migrant workers. Almost 90 percent of the country’s population are foreigners.

“The World Cup would not have been possible without them,” McGeehan added of migrant workers. “They build and sustain everything. If they disappeared tomorrow, the country would cease to function.”

After years of criticism and news coverage related to the plight of migrant workers, Qatar enacted some of the most comprehensive labor reforms in the region. They include the abolition of the kafala system, a type of labor contract that tied employees to a single employer but which led to frequent abuses. Qatar also introduced a minimum wage, the equivalent of almost $300 per month.