Barrett will be a key man for the All Blacks against the Lions.

Former All Blacks playmaker Nick Evans would "drool" if he could utilise Beauden Barrett at Harlequins after stating he would definitely favour him to Lions linchpin Owen Farrell.

Evans, 36, will become Harlequins' attack coach for their next season after announcing his retirement in April.

Farrell kicked four penalties to beat the Crusaders 12-3 on Saturday and led the Lions superbly in Christchurch; operating at first and second five-eighth in unison with halfback Conor Murray and Irish No 10 Johnny Sexton.

GETTY IMAGES Nick Evans would prefer Beauden Barrett to Owen Farrell.

But Evans would "100 per cent" prefer to have Barrett at first-five because he's "probably the most dangerous unstructured player in the world".

READ MORE:

* Henry: Lions a 'dangerous beast'

* Barrett ready for Lions speed

* Blitz defence can speed up

* Hammett downplays scrum drama

* When farmers beat the Lions

"The Kiwi that I am, I would love to see 10s play that way," Evans told the BBC of Barrett.

"If he was playing for Harlequins, he's got [England halfback] Danny Care inside him. Those two types of players and attacking rugby, I'd drool all over that.

"When he's at his best, he's absolutely on another planet. He's got the pace, he's got the ability, he's just got that nous to ghost into gaps and he's always playing on that front foot."

Evans acknowledged that some facets of Farrell's game - goal kicking and general kicking - were superior and that he'd been brilliant for the Lions in outings against the New Zealand Provincial Barbarians and the Crusaders.

JOSEPH JOHNSON/FAIRFAX NZ Farrell booted the Lions to victory against the Crusaders.

But Evans said: "I think Beauden's probably a lot better at the offensive kicking - the little cross kicks, the little nudges in behind. Things like that."

The Saracens and England five-eighth has been named on the bench for Tuesday night's Highlanders clash with Dan Biggar starting at first-five, but Farrell is the name on everyone's lips to start at 10 or 12 against the All Blacks.

"He's playing the game plan that the Lions perfectly, he's playing territorial, positionally brilliantly," Evans said.

GETTY IMAGES Evans has become a Harlequins legend since leaving New Zealand in 2008.

"I think he managed the [Crusaders] game well in terms of calling plays, the right plays at the right time, the structures they need, bringing in players that he needs and his passing was brilliant as well."

Evans, who won 16 All Blacks caps between 2004 and 2007, said Farrell and Barrett wouldn't clash much if they were opposing 10s during the test series, but thinks their influence will be pivotal for either team's chances.

"It's more mentally who's going to dominate the game in terms of tactically and structurally what they need to get," he added.

"That'll be the thing for me and maybe actually a big turning point on who comes out and trumps.

"We saw the Crusaders shut the Hurricanes down a few weeks ago, so he [Barrett] is human if the Lions do get in his face, but if the All Blacks get that front foot ball, there's no one better in the world so look, he's probably got that advantage at the moment."

The Lions face New Zealand Maori in Rotorua on Saturday and the Chiefs in Hamilton on Tuesday before the test series begins at Eden Park on June 24.