text: The Cheetahs and Kings are set to enter the league for the coming season, which begins in early September.
  The pair meet in their final Super Rugby fixture on 14 July, leaving scant opportunity for rest and preparation.
  "They're not having a break at the end of a strenuous Super Rugby season," Solomons told BBC Scotland.
  "They're going into a competition that is literally nine months. It'll be brutal for them. That is massive.
  "Players are very, very well-conditioned today, so the collisions are mighty. I think that is brutal and the logistics, in my opinion - they will have to play away from home for about three weeks at a time.
  "They'll have to come out on a three-week tour and play a block of games together. And then sides coming to South Africa will have to play both [South African] sides."
  The Cheetahs and Kings are expected to be cut from Super Rugby by the South African Rugby Union on Friday 7 July as the tournament is reduced from 18 to 15 teams.
  The expanded Pro12 may be split into two seven-team conferences, which would likely reduce the number of fixtures and volume of travel required.
  South African Solomons, 66, says spending long periods overseas would handicap the new additions.
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  "You're not practising and living at home - that's the disadvantage," he said. "You're not sleeping in your own bed in your own home environment.
  "The South African sides are at a distinct disadvantage, there's no question about that.
  "But I think we have always felt like we were at a disadvantage geographically in Super Rugby and had to travel more than the others - there's little you can do about it.
  "Your first game when you go to New Zealand is very difficult, because you're knackered. It takes about 10 days to acclimatise.
  "And now, with the teams going across to the UK, there is no change of time zone.
  "It's an overnight trip. There will be a bit of jet-fatigue but no jet-lag. I think what is going to fatigue them is doing it multiple times. That has never been done before. They may reduce the number of trips, but it's still going to be brutal."
  Solomons has coached the Kings and Stormers in his homeland, as well as assisting Nick Mallett with the national side and working as a high performance consultant for the game's global governing body, World Rugby.
  North of the equator, he has led Ulster, Northampton Saints and Edinburgh, whom he left after three years in September 2016, and spent the second half of last season with Bristol in a consultancy role.
  The veteran coach believes both franchises would adapt well to their new league.
  "Knowing the Pro12, both those teams as they are operating at the moment are well capable of being competitive," he said.
  "The Pro12 has always been a cross-border competition - none of the nations could have their own domestic competition because they don't have sufficient playing numbers within their countries.
  "I think it is a natural fit to have the Kings and the Cheetahs come in from a cross-border perspective. I think there will be benefit to both parties.
  "It will be marvellous for [the existing Pro12 teams] to travel to South Africa and compete in a completely different environment.
  "I do think there will be good support for the Cheetahs and the Kings - certainly there will be bigger television audiences and I think that'll help [the Pro12].
  "Hopefully, there will be more money coming into everyone's coffers due to increased broadcast revenues and the competition itself will generate better revenue, which will help with the travel."
target: South African inductees to the Pro12 face a "brutal" transition from Super Rugby, former Edinburgh head coach Alan Solomons has warned.