Tomorrow's game between Australia and England might be the first of seven one-day games between the two sides, and it might ostensibly be a match to celebrate the 40th anniversary of one-day internationals, but the real truth is that for many of the players involved, the World Cup starts here, not in 34 days time.
England will field what is pretty much a full strength side at the MCG, but two vital components of their normal XI will be missing: the injured Stuart Broad and the rested James Anderson.
That gives an opportunity for Chris Woakes and Ajmal Shehzad to stake a claim for a place in the World Cup squad.
In reality, Woakes' performance in the T20 internationals puts him far ahead of Shehzad, but it still doesn't mean he is in the same class as the two missing players as a bowler.
England badly missed the control that they can give at the start of an innings during those two games and there are teams better placed to take advantage of that than Australia are.
The contest among the English batsmen is not so much to get into the squad as to get into the side. The return of Andrew Strauss means that Ian Bell is likely to drop to three in the batting order and Kevin Pietersen to four, with all-rounder Luke Wright missing out altogether.
But this means no place for Jonathan Trott, who, it must be remembered, began his England career as a one-day player.
Write can consider himself unlucky to drop out, especially given the form of Paul Collingwood in a similar role, but he remains very much a part of the England plans. Trott will hope that he is in the same boat.
Australia have taken the intriguing decision to leave Nathan Hauritz in Sydney, with chairman of selectors Andrew Hilditch stating that he was never going to take part in this game anyway.
This must either mean that Hauritz has finally won Hilditch over and is already in the World Cup squad, or that he has no chance of making it. In all, it is just one more act in a dispiriting summer for the off-spinner.
Elsewhere in the side, Michael Clarke, Brad Haddin and Mike Hussey return, meaning there are no places for David Warner, Tim Paine or Friday's hero, Aaron Finch.
For Paine and Finch, their time will surely come again, but Warner must be wondering what he needs to do to make the 50-over side.
The Aussies also rest Mitchell Johnson, who looked far happier in the 20-over format than he did in the Test arena, and Steve O'Keefe drops out altogether.
Xavier Doherty gets the spinners berth and Doug Bollinger replaces Johnson, with neither change likely to enhance the side.
In some ways, it is the start of a meaningless series, with bragging rights alone at stake. But to some of the players, the next seven games are going to mean everything.