British and Irish Lions centre Jamie Roberts says while his side’s backs may have the size advantage, the Wallabies possess one of the world’s toughest backlines to defend against.

Roberts, more than anyone, would know.

The last time the 26-year-old medical doctor tasted success against Australia was in his debut international season for Wales in 2008.

“I only lasted 10 minutes. Me and (Stirling) Mortlock clashed heads, so I got credit with winning us the game,” he said.

“Not a lot of guys in the squad would have beaten Australia. Hopefully we can come together, be a stronger force, and beat the Wallabies.”

In fact, Roberts has been involved in the majority of Wales’ last eight straight defeats at the hands of Australia.

He says he’s looking forward to a little payback.

“I played in that game in November when we lost with that last-minute try by Kurtley Beale,” he said.

“It was the toughest result to take, absolutely brutal losing in the last second.”

Despite Beale being likely to miss the Lions series, Roberts said he’d been impressed by code-hopper Israel Folau at fullback.

“He’s a very talented player, I’ve seen glimpses of him play,” he said.

“But as are the entire Australian backline. They’ve always been one of the toughest to defend against.”

Weighing in at 110kg and standing at 193cms tall, Roberts epitomises the physical backline preferred by Lions coach Warren Gatland.

“Some of the backs are very good rugby players and very big athletes,” the 53-Test cap player said.

“Guys who can cross the gain line, who can play an expansive game but also who can play a power-based game.”

One challenge facing the Lions has always been gelling together the players from the four different nations.

However Roberts says his squadmates had gone back to basics with a few pub sessions to strengthen their combinations ahead of the opening tour match against the Barbarians in Hong Kong on June 1.

“Its about doing activities, having a few beers together, having a good time, and becoming good mates off the pitch,” he said.

“That way you make sure you don’t want to let your teammate down on the pitch.”

After England’s 2011 World Cup campaign was almost derailed by a team-bonding session gone too far, Roberts assured reporters his new teammates hadn’t been a bad influence at the drinking sessions.

“No certainly not. I dont think we have any players small enough on our team to let us do any dwarf throwing amongst ourselves,” he said.