The ANZ Stadium in Sydney will be the venue for the 27th time the two Welsh centres have teamed up together in the international arena and to reach that landmark Roberts had to spend three weeks on the physio table and Davies had to hold off the threat of the most iconic centre of his lifetime, Brian O'Driscoll.
The selection announcement for the series decider this week brought its own drama but, as Davies pointed out, it also showed the sheer class of those who didn't make the matchday 23 and enabled the great Welsh midfield pair to have a fourth crack together against the Aussies.
"I'm just grateful for the opportunity to play in such a big game. Brian is one of the greats because of what he's achieved and I was very grateful to him for coming up after the team was announced and shaking my hand and congratulating me," said Davies.
"That's the way the whole squad has been and everyone's been really close together.. Everyone who isn't involved on Saturday has shown a professional attitude - that's been one of the positives of the tour.
"It has been great to be part of this squad because everyone's got their focus on the game. Everyone has to deliver on Saturday and we're in the last chance saloon, we have to win.
"I was obviously over the moon to be involved in such a massive game and training has gone really well this week. It's a huge task and we're really focused on the task in hand. I was glad to get the nod and I'm looking forward to taking my opportunity again."
Davies has played more minutes on tour than any other player and it was his outstanding performance alongside Roberts in the 47-17 win over the Waratahs the last time the Lions were in Sydney that propelled him into Test contention.
The hamstring injury suffered by Roberts late in that game meant Davies went into the first two tests playing in the slightly unfamiliar position of inside centre, with O'Driscoll playing outside him. On Saturday he will be back in his favourite No13 jersey with his Welsh partner back on his inside.
"Jamie has a big, physical presence and gets over that gain line. Just the way he works after training with his skills, he's done extremely well over the last couple of weeks to get back fit," said Davies.
"To have someone like that come in shows the strength of the squad. It is a benefit that I've played a fair bit with him at international level. What he brings is something different and I'm looking forward to playing with him again - it's an exciting prospect.
"We all know how big and important this game is and we're looking forward to doing the job on Saturday. All the boys are focused and we've had a good couple of days of resting up and then good training.
"We're ready to the job. It's one of the biggest games of my career and I can't wait for the opportunity now."