Wales' Jonathan Davies will be "the midget of the midfield" if Ireland pair Stuart McCloskey and Robbie Henshaw at centre for Sunday's Six Nations opener, according to Conor O'Shea.

Davies boasts the size and physicality to dominate any Test midfield, but could yet be dwarfed by the men around him in Dublin this weekend.

At 6ft 1ins and 16 stone, Davies could find himself conceding two inches in height to Connacht’s Henshaw, and a stone in weight to Ulsterman McCloskey.

Wales powerhouse Jamie Roberts is likely to prove the biggest centre on display at 6ft 4ins and 17 stone, leading former Ireland full-back O'Shea to predict some seismic collisions.

“Robbie Henshaw’s massive and McCloskey’s a big lad too — so Jonathan Davies could be the midget of the midfield,” O’Shea said.

“That’s incredible to think.

“Everything I’ve seen of Stuart McCloskey, there’s a huge amount to his game.

“He has beautiful soft hands on top of being a massive, massive bloke.

“If Ireland put Robbie Henshaw and McCloskey together, that could be one hell of a battle.”

Ireland head coach Joe Schmidt has branded Wales "the biggest team in the world" ahead of facing Warren Gatland's unremitting side at the Aviva Stadium.

Schmidt believes a top-half Six Nations finish would represent success for Ireland, even though the reigning two-time champions will chase a record third-straight title.

Pairing the uncapped but in-form 23-year-old McCloskey with Connacht battering-ram Henshaw would prove Schmidt’s most obvious method of combating Wales’ unchecked physical approach.

The former Leinster boss could yet reprise his favoured midfield combination of Henshaw and Jared Payne, however, in a move that would befit his tendency to play the percentages.

Harlequins rugby director O’Shea has had the chance to get up close and personal with Roberts after luring the qualified doctor to The Twickenham Stoop this season.

O’Shea admitted he was taken aback by the sheer size of Wales’ 29-year-old midfield fulcrum on his west London arrival.

But while Roberts plays to his muscle-bound strengths of ploughing straight lines over the top of opponents, O’Shea insisted the 74-cap Wales star possesses far more subtlety and variation to his game than many realise.

“I really didn’t realise just how big Jamie is until he arrived here and he got stuck into training,” said O’Shea.

“He’s extremely hard to stop, and he’s in great shape for the start of the Six Nations.

“He’s a really outstanding rugby player. You can’t achieve everything he has without that.

“There’s far more to his game than just this line he runs — but he runs it well.

“It’s his talking on the field, how he organises.

“He’s got miles better hands than people realise.

“That sounds a terrible thing to say, but it’s a big compliment.

“You can’t thrive at that level without all the skills and attributes. But he knows what his strength is.”