Throwing Qatar’s appearance in the Asian Cup final in doubt, organisers are investigating a complaint by the United Arab Emirates about the eligibility of two Qatar players from the semifinal.

The complaint adds another layer to Qatar’s politically charged progress to Friday’s final of the continental soccer showpiece in the UAE, which as a country is part of a quartet boycotting Doha diplomatically and politically.

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

The UAE soccer federation has now questioned whether Ali, with a tournament-leading tally eight goals, and Bassam Al-Rawi meet FIFA’s requirements to play for the 2022 World Cup host nation.

“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. Qatar is due to play Japan on Friday in its first-ever Asian Cup final.

Qatar coach Felix Sanchez, however, insisted the 2022 World Cup hosts were confident ahead of the country's first appearance in the final after comfortably winning all six of their matches and keeping a record six clean sheets.

"To us it's no surprise that we are in the final," said the Spaniard, who has received messages of support from Jose Mourinho and Arsene Wenger.

"I have full trust in the players, they are motivated to make history."

Sanchez dismissed fears of AFC action.

"I'm not concerned at all," he shrugged. "All the players are working with us, so no worries."

Yoshida blasts Asian Cup 'stupidity'

Meanwhile, Japan captain Maya Yoshida warned that problems on and off the pitch are embarrassing the Asian Cup.

The Southampton defender called on tournament organisers to deal swiftly with incidents of "stupidity" that, according to Yoshida, risk damaging the reputation of Asian football.

"I think the AFC should control stuff about penalties and suspensions," Yoshida said Thursday, noting also that Japan's tempestuous 3-0 semi-final victory over Iran had ended with rival players almost coming to blows.

"But I would mention that if (the tournament) is broadcast all over the world, you don't want to see any stupid things, especially after the game," he added.

"We are representing Asia under the hashtag #bringingasiatogether ─ so it's important to represent Asia by playing good football and with fair play."

The tournament slogan has rung hollow in the Emirates, where finalists Qatar have been frequently abused by hostile local fans over the Gulf blockade of the tiny, energy-rich state.

Japan's upset of title favourites Iran also came close to boiling over, with Yoshida himself needing to be restrained by team mates after reacting furiously to a petulant slap from Sardar Azmoun.

The Asian Cup has seen its share of controversial refereeing decisions, with hosts UAE twice awarded soft late penalties that left rivals players and coaching fuming.