And with many eyes fixed on Saturday's game against England, today's clash with Fiji at Rodney Parade, Newport, will provide even more valuable practice.
Melrose is quick to point out that he not yet thinking about Saturday's game against Nigel Redman's England team despite accepting that others believe it will settle the Pool.
Still, there is little doubt that this evening's game will be a useful exercise for a Wallabies' side who have already shown what they are capable of achieving.
He said: "Because of the Super 14 commitments, we actually spent zero days as a squad preparing for this competition. That is why we are trying to cram in as much work as possible.
"We were pleased with certain aspects of the game last weekend and we hope to be even better than that against Fiji. We know they will provide is with a real challenge, so we have to make sure that we are on top of our game."
Meanwhile, England take on Canada in this evening's early Pool C game with coach Redman hoping to see his side reproduce the form they showed in the first half against Fiji four days ago.
They won that game 41-17 although the side failed to rack up a single point after half time.
Redman has rung the changes for the side's second game, with four players making their first starts of the season whilst half a dozen more play their first game of the competition.
Bath prop Billy Moss, Northampton lock Courtney Lawes, Newcastle centre Alex Tait and Gloucester wing Charlie Sharples have not started for England U20 this season, whilst starting their first game of the Junior World Championship are Luke Eves (Bristol), Rob Miller (Newcastle), Ben Youngs and Gregor Gillanders (both Leicester), Joe Gray (Northampton) and Matthew Cox (Worcester).
Tickets for all Junior World Championship match days are £2 for children and £8 for adults and are available at all match venues right up until kick-off.
Pool C (Rodney Parade, Newport)
5.00pm England v Canada
7.00pm Australia v Fiji