British and Irish Lions 2013: Midweekers rolling Melbourne Rebels is key to tour, says Graham Rowntree

Manu Tuilagi trains yesterday ahead of the match in Melbourne (Getty images)

Graham Rowntree agreed on Monday that the injury-hit Lions now had something of a "siege mentality" about them. If they lose on Tuesday against a strong-looking Melbourne Rebels team – a side more cohesive than any of the depleted Super 15 outfits previously encountered – the tourists will find themselves besieged by doubt. Make no mistake: this game matters.

"The attitude shown by the midweekers, the intensity generated by them, can make the tour," Rowntree said. "These guys were the first in the dressing room in Brisbane last Saturday, congratulating the Test players on their victory, and they were the first up on Sunday morning to get out there and train for this match. They're vital to the success of this trip."

A week ago, the Lions lost to the ACT Brumbies in Canberra – their first defeat against provincial opposition in 16 years. It was not wholly calamitous: the tourists fielded a make-do-and-mend back division featuring three players, the wings Shane Williams and Christian Wade and the centre Brad Barritt, who had virtually gone from airport to stadium without passing "Go".

There was, however, some consternation at the way a very decent forward pack was dominated at the breakdown.

Today, the midweek pack contains players with more legitimate designs on a place in the 23-man squad for the Melbourne Test this weekend, not least in the back row, where the Wales No 8 Toby Faletau will be flanked by his countryman Dan Lydiate and the Irish forward Sean O'Brien.

Lydiate captains the side thanks to the withdrawal of the England lock Geoff Parling, who will now face the Wallabies on Saturday after Paul O'Connell was ruled out of the rest of the series with a fractured arm.

"That Brumbies defeat didn't go down well with us," Rowntree remarked. "There were a few playing that night who are involved again and it's a chance for them to put things right. We're having to roll with the punches at the moment, so this game is important to us. We've said right from the start that the midweek attitude is at the heart of what we're trying to do."

If last week's arm wrestle in Canberra was something of a one-dimensional contest, albeit an enthralling one in its own Jurassic way, today's game promises something very different in terms of tempo and pizzazz.

Damien Hill, the Rebels coach, has been able to field something resembling his Super 15 first-choice combination, leaving aside the Wallaby contingent of James O'Connor, Kurtley Beale and Nick Phipps.

"There are not too many chinks in the Lions armour, but we're taking the approach that we want to be true to the Rebels' style of play," said Hill, who has been in charge of Australia's newest Super 15 franchise since the start of last year's southern hemisphere season.

"We'll have to be a lot smarter and more clinical than we have been to stand a chance, but there is always a chance.

"We have a number of aspiring Wallabies and there's no better arena for them to be in to test their skills."