Steve Hansen said it is unlikely that Israel Dagg, Aaron Cruden and Ben Smith will all still be playing for New Zealand beyond next year and thinks England can break the All Blacks' world-record winning run.
Dagg, Smith and Cruden will be in the final year of their New Zealand Rugby contracts in 2017 and have been linked with big-money moves to Europe.
All Blacks head coach Hansen knows he is likely to lose at least one of the trio given the financial might which top clubs in France and England have at their disposal.
"It's going to be touch and go I think. We're trying really hard to keep them," he told Radio Sport.
"Will we keep all three of them? Probably not. But if we can keep two out of the three that'll be a positive, if we can keep all three that'll be extraordinarily positive.
"You're never going to retain everybody because we just don't have the same amount of money as the English and the French do, and that's just a reality we have to come to terms with."
The world champions set a new record of 18 consecutive Test wins against tier one nations in October before finally losing to Ireland in Chicago.
However, England have now reeled off 14 victories in a row and Hansen says Eddie Jones' side are more than capable of eclipsing the mark set by the All Blacks during the Six Nations early next year.
Asked if England can break the record, he said: "Of course they can, they've got the mental fortitude to continue to get up every week and play well.
"They've got games against Italy and you'd expect them to beat Italy and I'd expect them to beat Scotland so they've then got the Irish game, the French game and the Welsh game.
"They'll be toughies, but we know they're capable of beating them. They went through the year undefeated so it's there for them to have a crack at."