"Gavin Scott is expected to arrive in New Zealand on Sunday in time to train with us in Napier. He may be available to take his place on the bench for the tour match on Tuesday," Scotland manager Douglas Morgan said.
Glasgow Caledonians' Gavin Scott will replace Brotherstone who picked up he injury against the New Zealand Maoris last Saturday.
The Brive player will fly home on Sunday, the same day Scott is expected to arrive.
Martin Leslie, who returns from injury in this Saturday's Test against the All Blacks, has re-signed for Edinburgh Reivers for three years.
"Gavin Scott is expected to arrive in New Zealand on Sunday in time to train with us in Napier. He may be available to take his place on the bench for the tour match on Tuesday," Scotland manager Douglas Morgan said.
It is the second time Scott has replaced an injured national player on tour.
Two years ago he filled in for Gordon Bulloch in the first test when Scotland toured Australia.
'Delighted'
Scott said: "I am absolutely delighted, if a little surprised.
"When I got the call from Dougie Morgan to say I had a couple of hours to pack, I couldn¿t believe it had happened again. At least this time I have an extra day compared to my arrival for the Australia tour in 1998."
Brotherstone was examined by Scotland doctor Ken MacKenzie and his opinion that Brotherstone would not recover in time to be considered for next weekend¿s second Test in Auckland was corroborated by New Zealand doctor John Mayhew.
"The New Zealand union very kindly said that Steve could stay on the tour if he wished, but Steve decided to decline this offer and will be leaving for home on Sunday," added Morgan.
25-year-old Scott was a member of the Scotland A team and the Scotland squad in this year's Lloyds TSB Six Nations Championship.
Meanwhile, Leslie has re-signed for Edinburgh Reivers for a further three years.
Leslie had been the subject of interest from clubs in England and France but opted to stay at the Reivers.
Reivers chief executive Nick Oswald was delighted at the capture of another long-term re-signing following those of Chris Paterson and Graham Shiel.
"We are very pleased that Martin has pledged his rugby future with the Reivers," said Oswald.
"He is a special player whose abilities are self-evident."