Australia's record scorer Tim Cahill moved closer to a move to the A-League after Football Federation Australia (FFA) approved the introduction of full season guest players for the 2016-17 season.
It opens the way for the 36-year-old to leave Chinese Super League club Hangzhou Greentown to join Melbourne City with whom he has been heavily linked.
The guest player spot will be in addition to the current two marquee positions in 23-man squads, giving clubs the ability to spend more on regional and global superstars.
"As the A-League has grown, the standard of play has dramatically improved and we believe the creation of this extra position will allow for continued growth in performance but also marketability and visibility," FFA CEO David Gallop said in an official statement.
"The full season guest player opens the door for clubs to attract high profile players that not only bring talent and exposure to their market but the entire competition."
Cahill, who has spent most of the past two decades with overseas clubs, has never appeared in the A-League but was a youth player at National Soccer League sides Sydney Olympic and Sydney United.
If Cahill does join Melbourne City, the club will be playing in a different strip after FFA approved their proposal to wear blue, despite concerns from Sydney FC.
The change will bring the Victorian-based side into line with their global strategy under City Football Group, owners of Manchester City.
"The Board noted previous concerns raised by Sydney FC but felt that things have evolved since that time and with the increasing maturity of the A-League, the strength of Sydney FC's 'Sky Blue' brand and the many uses of light blue throughout previous and current Hyundai A-League playing strips, it is now appropriate to allow for the full integration of the City Football Group's playing strip colours," Gallop said.
"As part of the decision, Sydney FC will retain exclusivity of its 'Sky Blue' brand as Melbourne City adopts the 'City Blue' colours."
The 12th season of the A-League will begin in October, with Melbourne City away to Wellington Phoenix in their opening game on Oct. 8 before a Melbourne derby against Melbourne Victory on Oct. 15.
Former Everton midfielder Cahill, who played in three World Cups and three Asian Cups, has scored 47 goals in 91 internationals for Australia since making his debut in 2004.