Michael Venus's frustrations are starting to boil over.

The New Zealand doubles player will have to pull out of next week's ATP World Tour Finals in London if he can't swap his voucher for managed isolation in New Zealand from later this week to after the tournament this month.

If he doesn't fly home on Wednesday, the earliest he can get another voucher is February.

Venus says if he doesn't play the Tour finals his ranking will drop and jeopardise his chances of Olympic selection.

"Earned the right to play here in the finals with the top eight doubles teams from how we're done this year, and not playing here could have a big impact on the career.

"Could lose out on qualifying for the Olympics and that has pretty big implications."

Venus has someone he can swap with, but officials won't let him. 

Will Ward, Venus' Kiwi coach, told Heather du Plessis-Allan that it is a heart-wrenching situation for him as the goalposts kept shifting.

"He wouldn't land or be in February until New Zealand. That's not possible for an athlete at his level."

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