Gordon Tietjens believes it is inevitable that players will have to specialise in Sevens rugby as the build-up to the Rio de Janeiro Games in 2016 intensifies.
Currently the New Zealand Rugby Union have 15 contracted sevens players, most of whom also have 15s contracts with provincial unions as well. That squad will be expanded to 20 from next year.
But with sights set on winning gold when sevens rugby makes its debut on the world's biggest sporting stage, Tietjens feels playing both forms of the game will take too much of a toll on players' bodies.
"Looking down the track I think players are taking sevens seriously and they see it as a career path," said the New Zealand Sevens coach who has guided the team to four Commonwealth Games gold medals.
"They won't be able to do both. I think you'll see the addition of perhaps a lot more (sevens) tournaments. I know we'll have a couple of extra world series tournaments from next year.
"There just won't be time. We see the physical nature of sevens now too and I don't think the body will hold up to playing competitive 15s and also sevens."
New Zealand Sevens captain DJ Forbes is a case in point. He has led the team since 2007 while also playing for Counties Manukau. The 29-year-old will be a crucial part of New Zealand's quest for gold in four years' time but it seems unlikely he could continue to play both forms of the game and been in peak condition for Rio.
"In terms of the work-load and the demand it is hard to back up," Forbes conceded. "There are a few of us who have been doing it for four or five years no, going back into 15s straight after (the world sevens series);
"It would be good to have an off-season. But this is our job, our career. We're finding ways to play the bills. Playing the two forms is what we're doing to make ends meet."
South Africa already has a specialist sevens squad, while the United States recently announced it had contracted 11 players who would be based at the Olympic Training Centre in California.
"As good as New Zealand is, imagine how much better we could be if we had a specialised group of boys who just played sevens," added Forbes.