Mitchell was diagnosed with a ruptured tibial posterior tendon after the second Rugby Championship encounter with the All Blacks as his injury nightmare continued apace.
The 28-year-old had suffered a horrific ankle break in April of last year and then experienced further complications after a torn hamstring saw his World Cup campaign ended prematurely.
But now he finally has something to smile about after making a mockery of his initial prognosis to be named on the bench for Saturday's clash with the Kiwis in Brisbane - something that would have passed him by had he not enjoyed a chance family encounter on the Microsoft games console.
Mitchell was just a few weeks away from serious surgery when his niece and nephew persuaded him to join in with an Olympics-style game that surprisingly proved he could run and jump without any serious pain or discomfort.
"By the end I was running full-on, doing hurdles and all the rest of it," said Mitchell, who had been wearing a stability boot until he took the controller.
"There's still an element of not fully understanding how things are holding up - it's a pretty rare injury I have got.
"But it continues to improve, and I am doing all the strength tests everyone asks of me. I just have to be diligent with my rehab and keep strengthening everything around (the tendon), and I guess keeping a positive attitude.
"Each time I make the squad again, it's pretty special. There have been moments I wouldn't play again, or miss 12 months. So to be running around, and have the opportunity to play for the Wallabies, that's awesome."
Mitchell consulted doctors and physios after his enlightening experience on the Xbox and they were amazed to see his progress, especially as they confirmed that his tibial posterior tendon was still definitely ruptured.
The Waratahs star further shocked the experts by showing them how he could sprint up and down the length of the gym, and the rest is history.
So seven weeks after a setback that threatened to derail his entire career, Mitchell is back in the fold and ready to win his 60th cap at the Suncorp Stadium this weekend.
For an in-depth look at Mitchell's chances of featuring against the 2013 Lions, check out our Wallaby Watch feature, written just before his last comeback from injury, by clicking here.