Asian Cup hosts United Arab Emirates have launched a late challenge to get their regional rival Qatar disqualified by alleging they fielded two ineligible players at the tournament.

The complaint adds another layer to Qatar's politically-charged progress to the final of the continental football showpiece in the UAE, which is one of four countries boycotting Doha.

There was an angry reaction from the home crowd in Abu Dhabi on Tuesday as the UAE were routed in the semifinal, with shoes thrown at Qatari players after striker Almoez Ali scored the second goal in a 4-0 win.

The UAE football federation has now questioned whether Ali, who has a tournament-leading eight goals, and Bassam Al-Rawi meet FIFA's nationality requirements to play for the 2022 World Cup host nation having been born outside Qatar. Al-Rawi was suspended for the semifinal because of bookings, but would be in line to play in the final.

"The Asian Football Confederation has received a protest from the United Arab Emirates FA regarding the eligibility of two Qatar players," the governing body said in a statement on Thursday. "This protest will now be reviewed in line with the AFC regulations."

The ultimate sanction would see Qatar having to forfeit the match as a 3-0 loss, according to AFC rules, which would disqualify them from playing Japan on Friday in the final.

Almoez Ali trains with his Qatari teammates ahead of the Asian Cup final. Getty Images

Players can feature for a national team other than their birthplace if they comply with FIFA's requirements. Those include having a biological parent or grandparent born in the country or having lived continuously for at least five years in the country after the age of 18.

The 21-year-old Al-Rawi, who also played for Qatar at the Under-21 World Cup in 2015, is the son of a former Iraq international. The 22-year-old Ali is widely listed to have been born in Sudan, but that could not immediately be verified.

After winning the hosting rights for the 2022 World Cup in 2010, Qatar have had a long time to try to find the players to ensure they have a competitive team. The team's ranking has fluctuated between No. 78 and No. 112 in the last decade, a period in which they have never managed to qualify for a World Cup.

Both Ali and Al-Rawi are graduates of the state-of-the-art Aspire training academy in Doha that has been used to develop young talents, many of whom were born outside Qatar, a nation of only about 330,000 citizens.

FIFA referred all comments to the AFC. Qatar team spokesman Ali Salat did not reply to messages about the eligibility questions over players. and coach Felix Sanchez said at the news conference ahead of the final that he was "not concerned at all."

With Qatar having a point to prove about their footballing ability, Sanchez was more willing to talk about the landmark of the small Gulf nation contesting a first-ever Asian Cup final.

"[If] we get a result that gives us the trophy, of course, this will be a biggest achievement in the [country's] football history," Sanchez said. "It will mean that a lot of things have been done in the right way. In the last years, this group of players worked in the right direction with the right mentality to be in the top of the competition.

"[It] doesn't matter what happens tomorrow, we are feeling very proud about them, because they are showing very high level in this competition playing against top teams. So, we are going to try to make people in our country tomorrow happy again and try to make history."

Victory would perhaps be all the sweeter for the Qataris coming in one of the nations that have severed all ties with them over accusations they support extremist groups. Qatar denies any backing of terror groups.

Having blocked off direct travel to Qatar since June 2017, the UAE made no exemptions even to smooth the journey of the country's Asian Cup team. Qatar were forced to take a circuitous route via Kuwait lasting more than five hours to make an air journey that can be done directly in around an hour.