Hemopo has headed from Dunedin to Johannesburg to replace the injured Liam Squire who faces a race against time to be in contention to play the British and Irish Lions.
Hemopo was supposed to play club rugby for Green Island on Saturday but was scratched as he headed off on the long journey to Africa.
Squire broke his right hand thumb about 10 minutes into the game against the Cheetahs at Bloemfontein on Saturday morning (NZ time) and, although he tried to continue, he left the field shortly afterwards.
Highlanders coach Tony Brown confirmed Squire's break after the game. The rugged loose forward will return to New Zealand early this week.
Squire was all but a certainty for the All Black squad against the Lions but the injury puts him in doubt. He is almost definitely out of contention to play for the Highlanders against the Lions on June 13 and it is touch and go whether he will be right for the test series.
The first test in Auckland is set for June 24 while the All Blacks are set to play Samoa in a warm-up on June 16, which is under six weeks away. Typically, a broken thumb takes about six weeks to heal.
Also on the casualty list is fellow loose forward Gareth Evans who took a blow to his shoulder and was to have it scanned over the weekend.
He took the blow almost as soon as he got on the field to replace Squire but carried on.
At this stage, Hemopo is the only player heading over although possible replacements in the loose forwards are thin on the ground back in New Zealand
The side is set to take on the Bulls in Pretoria this Sunday morning (NZ time) and will want to play better than it did in its amazing comeback victory against the Cheetahs.
The Cheetahs led 41-24 with less than five minutes to go but the Highlanders scored three converted tries to run out 45-24 winners.
Brown admitted he thought the game was lost.
''Honestly, I thought it was gone. I was thinking about selecting the team for next week against the Bulls ... I had moved on to the next game and thought maybe we can get back to get a bonus point,'' he said.
Brown said the team showed great belief to stay in the game and its execution in the final minutes was the key to winning the game. The Cheetahs' loss of a player to a yellow card also helped.
The side was elated after the victory and Brown felt sorry for the Cheetahs, who had played some outstanding rugby
Marty Banks helped himself to 20 points in the win while others to play well included halfback Aaron Smith and forwards Dillon Hunt and Daniel Lienert-Brown.
In other games over the weekend, the Lions beat the Rebels 47-10, the Chiefs thrashed the Reds 46-17 and the Blues proved too good for the Waratahs 40-33.
Iin South Africa, the Sharks beat the Force 37-12 and the Crusaders ran out 62-24 winners over the Bulls, while the Jaguares pipped the Sunwolves 46-39 in Argentina.