Dan Biggar says it is vital for Wales' future that head coach Warren Gatland and his staff remain in place.
While Gatland has another four years on his deal, assistant coaches Shaun Edwards and Robin McBryde are out of contract at the end of the World Cup.
Attack coach Rob Howley's current deal expires next summer.
"It will be a massive, massive blow if we didn't hold on to any of them," said fly-half Biggar after the 23-19 quarter-final loss to South Africa.
"It is what has been so key for us, that consistency and familiarity of what goes on in our camp.
"It has been like a club side, you can't describe it any other way. We have been a club side for the last four months and it has been pretty special to be a part of."
|Like this? Read these...|
|Wales missed Adam Jones and Richard Hibbard - Ruddock|
|Wales keen to avoid England in Euro 2016 group draw|
|Jade Jones wins World GP Taekwondo gold|
Gatland signed a new deal in December 2013 that takes him through to the 2019 World Cup in Japan.
But defence coach Shaun Edwards is shortly out of contract and remained tight-lipped when asked about his future on the eve of Wales' final pool game against Australia.
Wales have reached a World Cup semi-final and quarter-final since New Zealander Gatland took charge in 2008, as well as winning three Six Nations titles, including two Grand Slams.
And Biggar says the consistency within the coaching set-up has been instrumental in Wales' recent success.
"Every single person in our back-room staff plays a massive role, from the masseuse to the head coach," he said.
"If we can keep as many of those together as possible, it gives us a great chance moving forward."
Biggar has impressed during the World Cup, amassing 56 points and praised for being among the tournament's most astute tacticians.
But the 26-year-old says Wales are not interested in plaudits or sympathy, with their tournament exit to the Springboks still painful.
"At the end of the day, we've lost a quarter-final and that's the way it is," he said.
"It is pretty raw at the moment, but in a few weeks we can look back and be pretty proud of our efforts. Ultimately, though, we have failed in our goal, which was to reach the final.
"The immediate feeling is that we've been knocked out of a World Cup quarter-final that we were leading with five minutes to go. It's going to take a little bit of time to get over that.
"I thought we just about did enough to win the game, but fair play to South Africa, that is what a quality team does.
"If we had taken one of our chances early on it might have been different, but we can look ourselves in the mirror and think that with everything that has gone on I don't think we could have given an awful lot more as a squad and management team.
"It has been such a group effort."
|More from rugby:|
|Get World Cup alerts direct to your phone|
|Rugby World Cup 2015 fixtures and groups|
|For the latest rugby union news, follow @bbcrugbyunion on Twitter|