Gatland explained: "The message at this level is: 'You have to be accurate'. Unless we criticise and point out faults, how do you get better?

"You can't just say to the players: 'Fantastic, well done, pat on the back and now let's train'. You need to improve them from week to week."

The players were taken aback by the blunt nature of the criticism they received following the win at Twickenham - but they also appear to be revelling in the challenge.

Captain Ryan Jones said: "We are professional people and it is not all high fives. We have been honest behind closed doors.

"The majority of us took a fair bit of flak but we can't afford to rest on our laurels.

"We only won one game last season and that was against England. One game doesn't make for a season."

Uncapped Cardiff Blues winger Jamie Roberts will make his debut while while Tom Shanklin starts ahead of Sonny Parker and Ian Evans has replaced injured lock Alun-Wyn Jones.

Scotland have made two changes following their disappointing opening round defeat to France.

Kelly Brown has come in at number eight while Chris Paterson will make his 83rd appearance for Scotland, taking him past Gregor Townsend to become the most capped Scottish back of all time.

Paterson, who replaces the injured Rory Lamont, needs only 11 points to surpass Gavin Hastings' record as Scotland's leading points scorer in the 5/6 Nations.

Coach Frank Hadden said: "We've had a dent to our confidence but the squad are now doubly determined to travel to Wales and battle for everything we can get to win on Saturday."