Ian McGeechan loves to see players “growing” into the Lions jersey. He has seen it happen many times, and in the second international of a series where, as now, the touring team trail.

Jeremy Guscott in Brisbane in 1989, Dewi Morris in Wellington in 1993, but how McGeechan needs to see that growth this afternoon at Loftus Versfeld, one of the most pitiless arenas in the rugby world.

There is no more knowledgeable head coach in the game and he knows that, in relative terms, this is not the strongest Lions squad with which he has been involved. But if the series with South Africa is to be levelled and taken through to Coca-Cola Park in Johannesburg next Saturday, then certain individuals have to stand up and demonstrate they are as good as the Springboks.

“South African teams have a bullying mentality, trying to dominate, pushing players off the ball, getting into their faces,” Warren Gatland, the forwards coach, said yesterday before the Lions flew from Cape Town to the veld. “I would be very surprised if any of the Lions took a backward step to any physical threat imposed by South Africa.”

Gatland is conscious that a week ago the Lions, by comparison with the likes of Bakkies Botha and Bismarck du Plessis, were too passive when the verbal insults were traded, although they let their rugby do the talking by the end. Now Paul O'Connell, for one, must produce the domineering displays he so frequently offers in Munster's red. Other, equally experienced players have to join him and the younger generation, having watched Jamie Roberts and Tom Croft grow in stature in the past four weeks, are coming to understand the demands of Lions rugby.

The broader question of whether another losing series will have an impact on the future of the Lions can wait. This match is about the very essence of sport, of the underdog travelling through a hostile environment and, during the journey, discovering something of its own soul. There is no doubt that this Lions squad has character; now we find out if it has the rugby intelligence and skill to impose itself on the world champions.

South Africa, in the stadium where four weeks ago the Bulls put New Zealand's Chiefs to the sword in the Super 14 final, will not change their approach much from the formula that put them on the road to success in Durban a week ago. They will seek to dominate the first phase, kick for territory and then take the points through the crushing physical strength they possess or by kicking their goals. When they have put the series to bed, they can expand their game in a manner many believe they could have done two years ago during the winning of the World Cup.

Last Saturday they made only one line break wheares the Lions made nine, and that includes neither of their tries, one from a rolling maul, the other from what one of the Lions management described as more of a “dent”. It is this physicality that the Lions must match and that, in second-phase play, they have failed too often to do. Only then will they give their backs a chance to exploit what will be a better-organised Springboks defence.

“Some of the rugby played [last] weekend showed some confidence and that we can play the game we want,” Brian O'Driscoll, whose rugby here has been so understated and so vital, said. “We have to bring that out from the kick-off because we can't afford to give them a 19-point lead and chase it back. Hopefully, we can play earlier in the first half, cut off the Springboks and make them work for their scores a little more.”

Of seven first-half penalty awards to South Africa in Durban, six were within kicking distance and, at altitude, that quota increases even more when you have goalkickers with the length of François Steyn.

The Lions must maximise the kicking of Rob Kearney and the presence at lineout and maul of Simon Shaw. They cannot afford to lose a couple of lineouts, as they did early in the first international, but Shaw must also find permissible ways of upsetting Botha and Victor Matfield.

In pure rugby terms, O'Driscoll and Roberts hold the keys to a success most will believe is beyond the Lions. If they can get under Springboks skins, as they did so successfully against Australia 20 years ago, that will be another stepping stone, but lose and there are no tomorrows, not for this squad, not for McGeechan.