Ben Youngs
Warren Gatland has made five changes ahead Saturday's second Test, bringing Ben Youngs in for Mike Phillips. (Reuters)

Warren Gatland has dropped Mike Phillips in one of five changes ahead of the British & Irish Lions' second Test against Australia this Saturday, replacing the scrum half with Ben Youngs.

Mako Vunipola returns at loosehead after Alex Corbisiero failed to recover in time from a calf problem he picked up in last week's first Test where the Lions took a 1-0 lead in the series, while Geoff Parling will replace Paul O'Connell, whose tour was ended when the Irishman suffered a fractured arm in Brsibane.

Tommy Bower and Dan Lydiate have also been brought into the side. Ulster winger Bowe broke his hand two weeks ago but has defied the odds to get himself back into contention and replace Welshman Alex Cuthbert, with the Lions head doctor James Robson hailing his return to fitness as "unbelievable."

Lydiate meanwhile replaces Tom Croft at blindside flank.

Although he has been declared "fit and available" by his coach, Phillips has not been able to fully take part in training due to a knee injury that affected in him in the first Test - and made him an easy target for the Wallabies.

"The decision was to rest him his week," Gatland said of his decision to replace the Welshman with Youngs. "He is potentially an important component of next week. Given the quality of the nines we have got, all of them have done a great job for us.

"We felt it was prudent to make sure he was 100% fit for next week."

Alex Cuthbert, who scored the Lions' second try in Saturday's win at the Suncorp Stadium in Brisbane, has dropped to the bench with Croft, where they will be joined by Conor Murray, Ryan Grant and Sean O'Brien.

"We said after the First Test that we had improvement in us and we are confident that this is the case," Gatland said.

"Several players have put their hands up this week and have forced their way into the Test side while several players have returned to fitness.

"This is typical of Lions tours. We want players to constantly push for selection, we then selcet who is on form and who is available. Based on that we have selected a squad that is capable of winning the Test and securing the series."

Lions team: Leigh Halfpenny, Tommy Bowe, Brian O'Driscoll, Jonathan Davies, George North, Jonathan Sexton, Ben Youngs; Mako Vunipola, Tom Youngs, Adam Jones, Alun Wyn Jones, Geoff Parling, Dan Lydiate, Sam Warburton (c), Jamie Heaslip.

Replacements: Richard Hibbard, Ryan Grant, Dan Cole, Tom Croft, Sean O'Brien, Conor Murray, Owen Farrell, Alex Cuthbert.