After impressing selectors with two outstanding Super 14 seasons with the Western Force and some eye-catching performances for the Wallabies, including two tries in the 29-29 draw with Wales last November, Shepherd was widely tipped to earn a place in the World Cup squad.
But a knee injury just two months before the selection of the 30-man squad hampered the talented full-back-cum-winger's chances.
However, Australia head coach John Connolly has let Shepherd know he is on the list of replacements if any injuries occur during their World Cup campaign.
"When you don't play a Test match in the Test series you are always going to find it hard to make it into a World Cup squad," said Shepherd, after playing a starring role in Perth Spirit's 35-25 loss to the Sydney Fleet in the Australian Rugby Championship this weekend.
"But he (Connolly) said 'keep your head up, keep training hard, you are just one step away' because you never know... if someone gets injured maybe I will get a call-up, maybe I won't. I've just got to play good footy and that is all I can do at the moment."
The 23-year-old admitted he was 'devastated' to miss out on selection in Connolly's original World Cup squad and had taken a month to come to terms with the blow, but has since re-focused on getting fit and putting in solid performances for Perth in the ARC.
"I was devastated - it is a horrible feeling to miss the World Cup," revealed Shepherd.
"Without trying to be arrogant in any way I thought that if I was fit I probably would have been there, so to miss out in those situations is bad.
"But I have dealt with that over the last month - it has been hard to see all the stuff going on and people leaving but for me at the moment it is about me getting myself right, about getting my body right and playing good footy."
The talented goal-kicker also revealed the last few months had been a learning curve for him and would hold him in good stead with any future injuries.
"I think I pushed it (my knee injury) a little too much a little too early," he said.
"Obviously that was the wrong decision now and it has turned out that I have torn the ligament completely and that set me back from a five-to-six-week injury to a 10-to-12-week injury.
"But that is the way these things go and I will definitely deal with it a lot differently next time - I understand my body a lot more and I won't go back and play until I am 100% ready in my heart.
"I may miss this one but hopefully I might be around for another two after this."