It would have been tempting for Warren Gatland to bask in the afterglow of the sumptuous tries delivered by George North and Alex Cuthbert as the British and Irish Lions defeated Australia last weekend.

He did not. Instead, the Lions coach has gone against sporting convention by making significant changes to his winning team for today's second Test in Melbourne.

It is a bold decision but it could also prove to be the correct one if the Lions are to return home as series winners for the first time since 1997. Two of Gatland's changes have been enforced by injuries – to prop Alex Corbisiero and second row Paul O'Connell – but it is the other three changes to the starting XV that say more about Gatland's appreciation of the true nature of a first Test victory. That result owed as much to Kurtley Beale's infamous slip and Australia's lack of a world-class goal-kicker than it did to the Lions' excellence on the counter-attack in Brisbane. They might have delivered an intensity which is a prerequisite of Test rugby these days, but Gatland will know his side also faded during the final quarter.

Gatland's changes, however, are that of a contented coach in charge of a confident squad. The only surprise is perhaps the decision to drop Cuthbert in favour of Ireland's Tommy Bowe, whose broken hand had kept him sidelined for three weeks. It is a big call, but Bowe is a formidable opponent as well as having the edge over Cuthbert when it comes to fulfilling the vital defensive duties.

There is method in the initially daft decision to bench Cuthbert, then, as there is in replacing the lithe Tom Croft with Dan Lydiate at No.6. With O'Connell and Corbisiero both missing, Lydiate will provide extra bulk and power and, as such, is a necessary safety measure.

Such physicality can seem like a blunt weapon with which to beat the Australians, but it is also considered to be an effective one. "This Lions jersey demands you to have no respect for your body and you must be 100% fit," said Rob Howley, the Lions assistant coach.

"The side that has been selected has Test-match animals that have made decisions in games. They understand what is required. We talk about 80 games of one minute – that is the concentration level you need. It's about the trust and the unity which you have in the team in attack and defence, it's about the side that takes the opportunity."

There will be an opportunity for Ben Youngs, the England scrum-half, who will start today in place of Mike Phillips. There is a temptation to dispute the move since Phillips is strong and physical, although he does not possess the same sense of dynamism as Youngs. The Leicester player is often a darting presence, capable of a quick pass and a high tempo and his style will be utilised to quell the threat posed by Will Genia.

The Australian scrum-half was sublime last weekend and was also at the heart of everything creative in an Australian side with the capacity to attack from anywhere on the field. Phillips struggled to get close to him in Brisbane. "We are aware of Genia's threats," said Howley. "We talk about Ben Youngs being equally a running threat, and we will pose problems around the ruck. It's about speed of ball and not giving them that."

So while five changes, a third of the team, might suggest the Lions are uncertain, in fact the opposite is true. Gatland, if anything, appears clearer in his strategic thinking than he was ahead of the first Test; he knows his side must be more disciplined and concede fewer penalties, he knows up front his pack is capable of providing the platforms for attack, and he knows he possesses an assured goal-kicker in Leigh Halfpenny, while Australia have opted to keep the faith in the uncertain boots of fly-half James O'Connor and Beale.

The one imponderable is the backlash the Lions might suffer from an Australian side playing for pride at a time when their reputation as a sporting nation is under review. Making history – and arresting a convention for near-misses – takes difficult, bold and positive decisions by rational coaches and quality players. On that score the Lions should complete their first series victory in 16 years, but by the narrowest of margins.