Sam Warburton's untimely hamstring injury leaves the British and Irish Lions without their captain for the final Test but opens the door for Justin Tipuric and Sean O'Brien to become Lions heroes.
The Lions captain suffered a hamstring injury in the 67th minute which forced the 24-year-old to trudge off prematurely as his side eventually succumbed to a 16-15 loss to Australia in Melbourne.
After initial questions about Warburton's form heading into the tour as he recovered from a knee problem, the Wales international justified his selection with a talismanic effort in the opening two Tests.
It said a lot that Waburton's departure and the subsequent absence of his ferocious defending that the Wallabies were able to overturn a six-point deficit - through Michael Hooper's try plus conversion - and tie up the series at 1-1.
"It is incredibly disappointing to be ruled out of the tour through injury," said Warburton.
"I wish the team all the best and hope I can play some part in the build-up this week. I am confident the boys can finish the job off and secure the series win."
However, Warburton's injury now hands O'Brien and Tipuric the chance to cement their place in Lions folklore when the tour heads to Sydney.
And, for this winner takes all encounter, Gatland should turn to O'Brien.
The Leinster man entered the fray minutes before Warburton's injury and made crucial yards for the Lions and his ball-carrying will be vital if the tourists are to relieve the Australia pressure in Sydney.
There is a real need for Gatland's men to start taking the game to the Wallbaies and getting over the gain line, and O'Brien, alongside Dan Lydiate and Jamie Heaslip, can help the tourists achieve this goal.
O'Brien is the heavyweight option compared to Tipuric, who is, admittedly, suited to an attacking game. But ultimately, who starts, will depend on Gatland's approach to the final Test.