BRISBANE  - Three years ago, Cricket Australia's chief executive James Sutherland suggested that Twenty20 was such a specialist game that the day might come when Australia could have completely separate Test and T20 teams playing on opposite sides of the globe at the same time. Effectively, that day has arrived, although this one-off occurrence is not quite what Sutherland had in mind. Australia's Test players have now flown to Chennai to prepare for the first Test against India, unquestionably the correct priority. But the packed schedule means they still need to put out a national team for this T20 against West Indies at the Gabba, without David Warner, Shane Watson, Matthew Wade, Glenn Maxwell, Mitchell Starc and Xavier Doherty, to name but a few.Apart from the captain George Bailey, it is hard to say for certain how many members of the squad for this match would be part of Australia's first-choice T20 side. Shaun Marsh, perhaps. James Faulkner might soon get to that point, and so might Aaron Finch. And that's about it. That's not necessarily a bad thing, although the fans buying tickets for the Brisbane match might disagree. A year out from the next World Twenty20, it gives the selectors a chance to have a look at some men who could push their cases. There is the uncapped quartet of Ben Rohrer, Joe Burns, Josh Hazlewood and Nathan Coulter-Nile, there is Faulkner, Ben Cutting, Ben Laughlin and Clint McKay, all jostling to become regular members of the T20 attack, while the batsmen Adam Voges and Aaron Finch hope to make the most of their last opportunity of the international summer.For West Indies, this is a chance to finish on a high after a miserable five-match ODI series. They are the reigning world champions in the Twenty20 format and there is no question that the short matches suit their dynamic style. But after such a lacklustre display in the 50-over games, can they switch on for their last outing of the tour?Ben Rohrer is a classic example of the national selectors having rewarded Big Bash League performances. A solid if not spectacular batsman for New South Wales over the past few years, Rohrer, 31, delivered with the utmost consistency for the Melbourne Renegades this summer. He didn't fail to reach double figures and scored 34 not out, 27, 18, 30 not out, 52, 35, 57 and 42, which put him fifth on the competition run tally. His strike rate of 152.06 was also the highest of any of the BBL's top 20 run scorers this season. His challenge is to show the selectors that this should not be a one-off appearance dictated by circumstance. On Sunday at the MCG, Johnson Charles scored his first century in any form of elite cricket during the fifth and final one-day international. It is true that he rode his luck and his technique has so many holes that Phillip Hughes' looks pure by comparison, but Australia's bowlers must consider Charles a danger at the top of the order. SQUADS:AUSTRALIA: Aaron Finch, Shaun Marsh, Adam Voges, Joe Burns, George Bailey (capt), Ben Rohrer, Brad Haddin (wk), James Faulkner, Nathan Coulter-Nile, Ben Cutting, Clint McKay, Ben Laughlin, Josh HazlewoodWEST INDIES: Chris Gayle, Johnson Charles, Darren Bravo, Kieron Pollard, Dwayne Bravo, Narsingh Deonarine, Devon Thomas (wk), Andre Russell, Darren Sammy (capt), Sunil Narine, Kemar Roach, Tino Best.