Roberts will miss the tour but reckons Wales can roar.
Jamie Roberts reckons Wales have a golden opportunity to clinch a southern hemisphere scalp in this summer's tour of Australia. .
Wales travel Down Under without Roberts but he believes the team can build on their tremendous year, which culminated in the RBS 6 Nations Grand Slam, by walloping the Wallabies.
"They've got an incredible chance down south in Australia this year," said Roberts. "I don't think there's been a better opportunity for us to go and claim a southern hemisphere scalp.
"The team are obviously on a high from playing a good brand of rugby. All the boys are very comfortable with each other and we are all used to what we are doing.
"The shape of the team is good and the majority of players look to be fit. Hopefully we can send a more or less full strength side down there. It will be exciting."
The Blues star will miss out thanks to a reoccurrence of a knee injury sustained back in March.
Ashley Beck and Twickenham Triple Crown hero Scott Williams are the front-runners to fill the midfield void when Rob Howley leads Wales 'Down Under'
And like in the Six Nations Roberts admits he may have a battle on his hands to get back into the Welsh side.
"There's a lot of competition for places in the centre," added the Cardiff Blues star. "Obviously Jon and myself have played there for the last couple of years.
"But Scott has proved himself this season. The job he did down at Twickenham was fantastic and he's been playing well domestically.
"Ashley Beck is another who has been playing well for the Ospreys and deserves his chance. These guys could come in and stake a claim. That's the environment we are in.
"It's up to me then to put in the performances for the Blues when I do return and earn my place back in the team."
The 25-year-old underwent an operation at the beginning of April. He is already off crutches and can walk, but faces a long rehabilitation process and the added pain of watching Wales from the sidelines.
"I'm going really well. The graft is strong enough to allow me to walk and do my rehab. But I'm not going to be able to run for three months. The ligament doesn't heal to the bone for at least 12 weeks.
I suppose it's going to test my patience, but that's the way it is. It's massively frustrating. Any player will tell you it's a strange place to be watching the team from afar. It's obviously very hard to watch."
As the countdown continues for RWC2015, Tournament Chief Executive Debbie Jevans visited the Millennium Stadium to discuss preparations for the eight matches and reveal the positive news that 100,000 tickets for games at the home of Welsh rugby have sold in the last seven days.
Jason Harries is targeting a first win on the World Series circuit this season with Wales. The series returns to action this weekend in Dubai where Harries is part of a team hoping to build from its efforts in round one in October.
Wales skipper Jevon Groves says his side have addressed a few points from Gold Coast and aim to 'hit the ground running' in the next two rounds of the World Series, kicking off with this weekend in Dubai before heading off to South Africa next week.
Wales Sevens manager Steff Thomas is hopeful his side can build from a quarter-final spot in the opening round of the World Series in Australia when his side take part in the forthcoming double header in Dubai and South Africa.