Given that Wales have gone eight games without a win, desperation for an overdue victory could easily result in them throwing caution to the wind.

But centre Roberts said: “Balance is key this weekend. We can’t afford to take a gung-ho approach and chuck the ball around.

“When we won 26-13 at Murrayfield two years ago, it was one of the most clinical performances we’ve seen from this Wales team, I think.

“We were outstanding for the first 50-60 minutes. It was one of those games where we worked very hard off the ball, and it paid dividends for us.

“We carried strongly and put them to the sword, and that’s what we need to do again this Saturday.”

Roberts, man-of-the-match on that occasion, returned to international rugby against England last week after missing Wales’ four previous Tests – but he touched the ball just five times.

Wales coach Warren Gatland has publicly stated the need for his midfield powerhouse to become more involved this weekend – and also for other players to utilise Roberts’ world-class skills.

“I am not a massive believer in statistics after a game,” said the Cardiff Blues star. “But, having touched the ball just five times, you have to ask the question why?

“Some of that is down to me looking for the ball more, but a lot of it was down to the game.

“It was just one of those matches where you don’t get involved. Sometimes you have them. I haven’t really experienced that at international level before, but it has happened at regional level.

“I don’t think it was the case that I played poorly. It’s a balance between carrying the ball and playing a role in the team and maybe keeping the width.

“I found myself on the wing quite a bit in phase play, holding the width for the team.

“Sometimes you are dealt that responsibility in a match. You are playing your role in the team by doing that and allowing someone else to have the ball in their hands, but I will certainly be looking to get my hands on the ball more.

“It’s important I am maybe a bit more selfish in my approach and just get the ball in my hands and boss it a bit more. That’s the way I need to be, I think.”

Key to the outcome of Saturday’s clash could be the fly-half battle between two players with wildly-contrasting styles.

Wales are banking on the game-breaking prowess of James Hook – albeit in his first Test start at 10 since 2009 – while Scotland have Dan Parks’ reliable tactical and points-accumulating presence.

Parks linked up with the Blues last summer, and Roberts knows how dangerous his regional team-mate can be.

“Having played with him at the Blues, Dan is a very good tactical and positional kicker and a very controlling fly-half,” he added.

“He is one of the best at controlling territory. He knows what he wants from the people around him, and he brings out the best in those people.

“Hopefully, we can maybe target him in defence. We will see if he’s done some tackling practice this week!”

Parks is among many threats in an expanding Scottish armoury being developed by coach Andy Robinson, who signed a contract extension until after the 2015 World Cup yesterday.

During the same eight-month period of Wales’ current winless run, Scotland have beaten world champions South Africa and toppled Argentina twice in South America, which is why they are clear favourites for Saturday’s contest.

But Roberts believes it is a dangerous game to write Wales off, claiming: “Certain facets of our game let us down against England, but I don’t think we played poorly in any shape or form.

“England executed better than us, but in patches we played very well and we defended very well. There is not too much negativity about the place – we are very positive.

“We can’t pretend that the pressure isn’t on us. It certainly is. The boys know that, but that will definitely bring out the best in us.

“How a team reacts to adversity is all-important.”