And Roberts, who ran in a try in the decisive third Test against Australia this summer for the Lions, admits his focus now switches to the RBS 6 Nations next year and being in the best possible shape.
"I am injured and I will miss out and that is professional sport," said Roberts.
"They have picked five centres and I am very confident those guys can do a sterling job
"As of Friday, I will be six weeks post operation and I am probably another four or five weeks away from playing.
"I am likely to be fit by the end of November, the doctors tell me.
"I just have to keep working hard, keep rehabbing well and keep being really diligent with my rehab.
"That [the Six Nations] has to be my goal now.
"Missing out on selection means it will be hard to watch but ultimately... it will drive me to be a better player.
"If those guys do well in the autumn, that will drive me to train harder to get selected for the Six Nations squad."