But Deans insists the Wallabies will relish the challenge on British soil.
"No involvement in the World Cup can be described as hell and when it comes around this group will be excited about what they're going into," said Deans.
"Tacking on England and Wales again is as good as it gets. They're great rugby venues and we love playing them.
"They will be playing the host nation, which will make the boys highly motivated, and Wales, with whom have enjoyed some tremendous matches,
"To be the best you have to deal with the best and that will be the case again."
But before the World Cup is next year's Lions tour of Australia.
Deans is relishing the challenge of taking on the famous tourists and he reckons the Wallabies will benefit from blooding several youngsters during their recent European tour.
"I'm excited about the Lions now," added the New Zealander. "It's a massive challenge but you only get one chance every 12 years and we will give it our best shot.
"It's been a tough year but we're confident that over time we will get the benefits of that.
"The good thing about the tour is that we now have blokes who are experienced playing in Test matches. They have been exposed to the game at this level
"We are a young group who have built up a lot of experience during a demanding year."