Socceroos' breakout star is set to become to most expensive Australian football player in history

Nestory Irankunda is in the sights of Portuguese giants Sporting Lisbon in a move which has the potential to make the Socceroos attacker the most expensive player in the history of Australian football.

Fresh from making his World Cup debut and scoring in Australia's only win - their 2-0 group stage victory over Turkey - former Adelaide United star Irankunda is reportedly nearing a permanent transfer to Sporting from English Championship side Watford.

The Lisbon club finished runners-up in last season's Primeira Liga and were the club where Cristiano Ronaldo began his career.

Sporting have qualified for the UEFA Champions League phase as a result of their second-placed finish, meaning that should he breakthrough into the first team, Irankunda has a chance to test himself against Europe's best.

Reports in Portugal indicate that in a deal that includes add-ons, Watford could pocket a total of €22 million ($A35 million) for the 20-year-old's services.

That would mean Irankunda surpasses fellow Socceroos teammate Harry Souttar, who moved from Stoke City to Leicester City in 2023 for €17 million ($A27 million) as Australia's most expensive transfer.

Irankunda played in 40 of Watford's Championship games last season, including 22 starts, scoring four goals and registering five assists.

Sporting would be Irankunda's third permanent move in as many years after joining Bayern Munich from Adelaide United two years ago.

After spending time on loan at Grasshopper Zurich, he was sold from Bayern to Watford prior to the start of last season.