It was only a year ago that Roberts played inside centre for the first time on the international stage for Wales against South Africa. Now he has risen to the heights of partnering Brian O'Driscoll in the British & Irish Lions Test side.
"On a personal level, it is nuts, crazy. This is the highlight of my rugby career - an unbelievable achievement," said the 22-year-old Roberts.
"I hope it will be an inspiration for any young player. We have seen Leigh Halfpenny and Keith Earls, guys who are younger than me, show they can reach this stage so early on in their careers
"For those young professionals in the academies it proves that if you really work hard enough you can reach this level in a couple of years."
Roberts was the man of the match in the big win over the Golden Lions and also managed to punch some very big holes in the Sharks' defence in tandem with O'Driscoll.
The Lions will be hoping he can do the same thing against Jean de Villiers and Adi Jacobs in the Springboks midfield in Durban to give the tourists a chance of winning the vital first Test.
"We have a fantastic opportunity as a Lions touring team to get a victory out here. We know this game is going to push us all to new limits," said Roberts.
"Fitness wise, we know how tough it is going to be. It is going to be like nothing the boys have ever experienced before, but the guys are getting mentally prepared for that.
"The adrenalin is going to kick in. We are game ready and raring to go."
Roberts is one of 10 new caps in the Lions starting line-up and will be the youngest player on the Lions side. Not that worries him.
"I have no fears about Saturday, only have enjoyment. I have been under pressure on this tour, but now the weight of the whole country is going to be on us," he added.
"The fans have come out and it is going to be very intimidating in the stadium. But I'm going to enjoy that - life is all about enjoyment and not being nervous
"It was a dream come true for me to play with Brian O'Driscoll earlier on in the tour. I watched him as a young kid and to play with him in a Lions Test is unbelievable for me being so young as I am.
"It is going to be an awesome experience. He is a world class centre and a good communicator and it is great to have so many senior players around me.
"I've obviously played with Stephen Jones with Wales and he and Brain will be calling the shots around me on the day. If I am a marked man, so be it, because it will create space for others.
"There are a lot of strike runners in our back line - Tommy, Ugo and Lee - and it is a
tasty side for sure."