British and Irish Lions 2013: Manu Tuilagi thrown in at the deep end on his debut

The last time the British and Irish Lions played in Western Australia, a dozen years ago, they made the peculiar decision to cast an outside centre as brilliant as Brian O'Driscoll in the unfamiliar role of full-back – an experience the Irishman enjoyed so much, he has never shown the slightest interest in repeating it. Tomorrow, in the same rugby backwater, his midfield partner will be the one playing out of position. It remains to be seen whether the great man has any more fun this time.

Manu Tuilagi's first Lions appearance will be in the No 12 shirt and while this is not a complete surprise – when Warren Gatland, the head coach, selected only one specialist inside centre in Jamie Roberts, it was obvious that someone would have to make do and mend – it is something of a calculated risk. The human bowling ball's flirtation with the position against South Africa last summer never had the look of permanence about it, and while he loses nothing to Roberts in terms of physical power, he is hardly a creative genius armed with a siege-gun kicking game. If it goes wrong, O'Driscoll may not receive a pass and be given nothing to chase.

O'Driscoll knows what it is to confront the Samoa-born Tuilagi and his special brand of South Seas-style scattergun rugby, and had a wry smile on his face when asked if he might find life easier being on the same side for once. "Wherever Manu goes, he creates holes," the Dubliner said. "Actually, I think he has a really good range to his game: people see his strong ball-carrying and his power in contact, but he has other skills that don't receive the credit they deserve. Where he runs, I'll be following."

Tuilagi then played his part in the mutual appreciation game, suggesting that O'Driscoll would be the man doing the leading. "Me following him? I reckon it will be the other way round," remarked the Leicester man. "He's the legend. I remember his famous try against the Wallabies on the 2001 Lions tour. Whatever he says during this game, I'll be like… yeah."

If Gatland is viewing Tuilagi as a genuine alternative to Roberts for the inside-centre role come the Test matches – for all Owen Farrell's decision-making frailties against the Barbarians in Hong Kong, he remains a pure outside-half in the coach's eyes – O'Driscoll's status as senior Lion and beating heart of the squad means he is just a couple of decent performances away from nailing down a starting place against the Wallabies. Listening to him yesterday, it was clear that the notion of playing midweek back-up to excellent Welsh centre Jonathan Davies had not occurred to him.

"People talk about the try I scored in the Brisbane Test back in '01," he said, having been reminded for the umpteenth time of his grandest statement in a Lions shirt. "But people also talk of the ferocity of the second Test against the Springboks in 2009, and of what happened to us in New Zealand in 2005." In other words, it has not all been wine and roses. Three Test series and three defeats? We really should be talking vinegar and thorns.

"None of us in this squad has won a series as a Lion," O'Driscoll emphasised to his audience. "I haven't lost any of the buzz about pulling on the shirt, but it's one thing doing that and another thing doing what we're here to do. We have to build our levels of ruthlessness. We have to make ourselves difficult to beat."

When he takes charge against Western Force in Perth, he will lead one of the most Irish-heavy sides in recent Lions memory: more than half the starting line-up will be from the Emerald Isle, including four of the pack – the prop Cian Healy, the hooker Rory Best, the flanker Sean O'Brien and the No 8 Jamie Heaslip – and both half-backs in Conor Murray and Jonathan Sexton.

Talking of the J-word, there is likely to be a renewed surge of support for a Jonny Wilkinson call-up as a result of Gatland's latest bulletin on his walking wounded. While O'Brien has been passed fit following a knee injury, the tour captain Sam Warburton is still struggling with a more serious version of the same issue. (Gatland expects him to be fit for the weekend meeting with Queensland Reds in Brisbane. If he fails to make that date, the Wales flanker's position in the squad will be a matter for serious debate.)

However, the principal medical concern right now is Rob Kearney. The Irish full-back, such an impressive contributor in South Africa four years ago, is not responding to treatment for a torn hamstring and is moving closer by the day to an early flight home. Should the worst come to the worst, Gatland will find himself under significant public pressure to send for Wilkinson rather than a like-for-like replacement.

Having finally completed a 10-month tour of duty with the reigning European champions Toulon – he missed out on a major double when he and his colleagues lost to Castres in last weekend's French Top 14 championship final – the World Cup-winning stand-off is now available to Gatland.

And while the coach believes him to be ill-suited to managing the kind of attacking game he wants his Lions to play, Wilkinson's big-match experience and ability to close out tight contests with the boot may yet play a part in the tour hierarchy's thinking.