He is widely considered as a shoo-in for a place in Warren Gatland's squad to jet Down Under and many expect to see a Test reunion with Brian O'Driscoll.
The duo were the centres of attention against the Springboks and Roberts describes the tour as the best experience of his career.
"It [the 2009 tour] was a huge stepping stone in my career, and I look back on it with very fond memories. It was certainly the best tour I have ever been on as a player," said Roberts.
"To play on that stage is the ultimate as a rugby player. It doesn't get any better.
"To make friends on tour with guys from other countries, guys you have grown accustomed to playing against, and seeing four sets of fans come together is a special experience.
"My old man went out in 2009 and made a lot of friends from England, Scotland and Ireland. It's unique in that way for players and fans.'"
Roberts, Brian O'Driscoll, Manu Tuilagi and Jonathan Davies are seen as the front-runners for the centre berths Down Under.
They face further competition from the likes of Gordon D'Arcy, Brad Barritt, Billy Twelvetrees and Matt Scott.
Roberts admits the prospect of touring with the Lions has been on every players' mind and he expects it to intensify in the coming weeks.
"I think every player will tell you that the Lions has been in the back of their minds since the start of the season,' said Roberts.
"It's there, it is itching away in the back of your head, and it is now within touching distance. Everyone has a chance to stake their claim.
"All you can do is go out and perform on the pitch every week, giving your all. If that's good enough then great, if it's not good enough then that is the way it is.
"It is up to the coach who he wants to select, at the end of the day, and what sort of players he wants to take on tour.
"The only thing you can do is perform for the 80 minutes, do your preparation in the week and make sure everything is right, ready to go. The 80 minutes is that window you get to prove to people what you are about.
"I train very hard, I work on my game and I go out and give everything during the 80 minutes on the weekend. That's all I can do."