By STEFFAN THOMAS

High hopes: Jamie Roberts playing for Wales

WALES might be Six Nations Grand Slam champions, 14 games unbeaten and ranked second in the world, but they have been warned to take their game to another level if they want to seal global glory.
Warren Gatland’s side have had a stellar 12 months, sweeping the rest of the Northern Hemisphere aside while also downing Australia, South Africa, and Argentina.
The gruelling preparations for the Japan World Cup have now begun with former Wales centre Jamie Roberts of the belief the team must make further strides forward.
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