LONDON - Tim Cahill's goal celebrations are well known around the footballing world, but his latest effort could land him in hot water with Fifa, who may investigate what appeared to be a "sponsored" celebration.
An investigation could be opened into suggestions the Australian was paid to promote an online travel agency after scoring an extra-time winner against Syria in the Socceroos' World Cup qualifying win at ANZ Stadium on Tuesday.
The striker's 109th minute header - his second of the night and 50th goal for his country - sent Australia through to an intercontinental playoff with Honduras.
But what happened in the immediate aftermath has prompted scrutiny from football's world governing body.
After the ball hit the back of the net, Cahill eschewed his usual box-the-corner-flag celebration, instead opting to outstretch his arms, in what appeared to be a physical interpretation of an aeroplane. He then made a T sign with his hands.
A Byron Bay-based travel company asked followers on social media soon after full-time if they had seen Cahill, their new brand ambassador, "doing the ... 'T'" at ANZ Stadium.
Cahill replied to the post with eight emojis, including a football and an aeroplane. The post has since been deleted.
"Always a pleasure,"he responded on his Instagram account. "Another chapter written and plenty more to come. Amazing team performance and really proud of everyone tonight, team, staff and fans. #FEARLESS."
The travel company is also a sponsor of Cahill's Melbourne City and its logo appears on the back of the club's shorts.
While there is nothing specific in Fifa regulations relating to a player using body parts to promote sponsors, there is a law on players' equipment which states a player will be sanctioned if they remove their jersey to reveal slogans or advertising.
This law would appear to extend to cover the removal of shorts, as Denmark striker Nicklas Bendtner found out in 2012 when he was fined €100,000 (S$160,415) for promoting a betting company on his underpants .
"Fifa is reviewing and analysing the reports from the referees and the match commissioners for all matches in Fifa competitions," a Fifa spokesman told Sky Sports. "Events which require further attention may be communicated accordingly."
It is not the first time Cahill's celebrations have made headlines.
When at Premier League club Everton, he apologised after celebrating with a "handcuff" gesture - a nod to his brother who had been jailed for an assault that left a man partially blinded in one eye.
During the Socceroos' World Cup qualifier against Kyrgyzstan in Canberra in 2015, he pretended to turn over the pages of a book before delivering his trademark boxing routine by the corner flag. He had just released a children's book and an autobiography.
On New Year's Eve in 2016 he attracted further attention, this time for not being able to celebrate in his usual style, after a Central Coast Mariners ball boy upended the flag before Cahill reached the corner of the pitch.