Coach Matjaz Kek has taken 26 players to the high altitude resort of Brunico in the Italian Alps to boost fitness levels and Ljubijankic, desperate to make the final 23-man squad, believes the hard work will pay dividends in South Africa.
"We knew there would be no breather after a long club season but playing in the World Cup is worth the sacrifice," he told the Slovenian Football Association website.
"I am honoured to be a part of the squad and to compete with the other strikers for playing time on the pitch.
"I'll do my best to get into the final 23-man roster and to do that I have to be at my absolute best."
"I am working my socks off to get a chance to play in the World Cup and if I am picked there is nothing I would love more than to score against England," said Ljubijankic, who netted twice in eight qualifiers.
He added: "We are a unit on and off the pitch, we are all good friends and team spirit is our greatest strength."
Slovenia were drawn in Group C with England, United States and Algeria, with their only warm-up for the finals against New Zealand set for June 4 on home soil in Maribor.
Should Ljubijankic make the final cut, the 26-year old striker will fulfil a long-term ambition of playing in a major tournament.
"I watched Slovenia take part in Euro 2000 and the 2002 World Cup and dreamed of playing on the big stage one day. That dream is now very close to coming true."
