Brad Shields came "very close" to New Zealand selection before opting to represent England, according to All Blacks assistant coach Ian Foster.

Openside flanker Shields will face the country of his birth in England colours this weekend when the All Blacks take on Eddie Jones' side at Twickenham.

Shields was born in Masterton, near Wellington, to English parents and played for Super Rugby side Hurricanes before moving to Premiership side Wasps and tasting Test rugby with England.

Foster said the 27-year-old knew how close he was to All Blacks honours when he headed to the northern hemisphere.

"I guess the obvious answer, which really is the only answer, is that the selectors didn't pick him," said Foster.

"It's like everything - when you're selecting a national team, there's a whole lot of good players that don't quite make it.

"He knew he was knocking on the door; he's a fine player and he was very close.

"So no, I'm not going to give you reasons why we didn't pick him.

"But what we do know is that he is a quality person, he did a great job off the field in the Hurricanes and he was in the conversation a lot with us.

"There will be a bit of banter (among the players) I'm assuming afterwards, but everyone's pretty focused on what we do.

"I think we've got over the stage of seeing him in a white jersey now. And he's just a loosey (loose-forward) who plays for England."

Shields represented New Zealand at Under-20s level but is now an integral part of Jones' England set-up.

His decision to change tack and chase honours with England has previously polarised opinion in the game, but Foster remained personally phlegmatic about the issue.

Asked if such moves are generally respected within the sport, Foster said: "I don't know; I think everyone's going to have mixed opinions on that.

"So you'll probably find people that are close to those players and family that might support it, then you'd have others with a different view on players jumping into a national team from another country so quickly.

"But look, it's an issue I don't really want to talk about. It is what it is; he's not alone, there's a few more in a few other teams.

"So it is what it is, in the current laws."