Harry Kewell has certainly had an impact on the A-League.
But the A-League's impact on Kewell may be just as long lasting.
The Australia star's return to England for family reasons after just 10 months in the A-League is a huge shock, particularly for Melbourne Victory which was convinced Kewell would re-sign.
As one of Australia's greatest exports who had never before played club football in his homeland, he arrived last August to a rock-star reception.
Kewell played near-packed houses around the country in what looks now his one and only season playing on these shores.
Now it's a tell-your-grandkids moment.
The A-League's highest-profile signing in its seven-year history is gone.
Did he provide great value? Yes, as a marketing tool. Yes, as a player.
The 33-year-old had a superb second half of the season after a patchy first - admitting the quality and standard of the A-League had taken him by surprise.
Kewell's body - so often maligned and a source of footballing let-down - was near perfect during his stint in Melbourne.
Eight goals in 25 games is a testament to both his output and durability in an under-performing team.
As Kewell's club lurched from crisis to crisis and coach to coach, he was not the problem.
The excitement factor and mainstream recognition that an Australian household name brought to the A-League are hard to quantify, and what void his exit leaves time will tell.
But what the A-League has given our most famous returning Socceroo may be a lot more than he expected.
In life, first impressions last. When it comes to signing footballers, it's last impressions first.
Kewell left England for Turkish club Galatasaray in 2008 as damaged goods.
He had spent his entire career playing there - a spectacular success at Leeds United and a spectacular failure at Liverpool.
So little did he play for Liverpool under a succession of career-threatening injuries that the critics wrote him off as crocked, and even worse in the eyes of the rabid British press, a crock on undeserved big-money.
Virtually chased out of top-flight English football, Kewell had a solid three-year stint in Turkey and for the most part, his body held up well.
Yet the Turkish league sits well under the radar for most interested in Kewell's career.
The A-League has provided Kewell a wonderful and accessible shop window.
His football for Victory - particularly on the left flank where he made his name as a teenager - showed he still has the quality.
So often the big question mark, durability now doesn't seem to be an issue.
His on-field future will be played out with the sad backdrop of tough times ahead for Kewell and his family.
Kewell's mother-in-law is gravely ill, prompting his return for the sake of his wife - English actress Sheree Murphy - and the couple's four children.
Even with the need to put his family first, Kewell will have to secure a new club to keep his career - and his ambition to play in the 2014 FIFA World Cup - on track.
Most likely that club will need to be in England's north - close to his family base near Manchester.
His A-League success could mean a mid to low-ranking Premier League club or upwardly mobile English Championship side could now be interested.
It gives Kewell the chance of a fitting twilight to his professional career where it started.
And it also allows him to fulfill his wish of giving something back to the A-League - though perhaps not in the way he may have imagined a few months ago.
The A-League's best chance of success on a broad scale is - and should be - as a reliable feeder league for the better European and Asian competitions.
Now it will send one of the country's greatest ever exports back into the English fray, repaired in body, reprieved in reputation.
If Kewell does shine when he returns to the field, it will give a measuring stick of the competition's quality against whatever league he ends up in.
And that could prove - under the ever-bright spotlight that Kewell commands - that the A-League can produce quality players for quality leagues.
The A-League will make its LIVE free-to-air TV debut next season with the blockbuster clash between Sydney FC and Newcastle Jets on Friday 11 October on SBS 2.