Serbia's reshuffled back four looked uncomfortable in three pre-tournament friendlies but the first signs of improvement were visible at their opening training session which had the makings of a competitive game.
"The defence is going to be the strongest link in the team despite poor form in the warm-up games but we have to defend as a unit," Lukovic told a press conference.
"You can't really divide the team into separate departments, we have to breathe as one when we come forward and when we retreat to retrieve possession."
Coach Radomir Antic seemingly has no selection dilemmas for Serbia's opening game against Ghana in Pretoria on Sunday, with his first eleven beating the reserves 1-0 in training thanks to several flying tackles in the closing stages.
"A lot of people see Germany as the group favourites but I think there is very little between the teams and I expect a four-way dogfight for knockout berths," he said.
"We've come here determined to show our quality and we will work our socks off although we have had a long season with our clubs, because there is nothing more important than the World Cup in a player's career."
While Ghana have the benefit of being coached by Serb Milovan Rajevac who will need no introduction to his compatriots, Lukovic believes the depth of Serbia's squad could make the difference in that game.
"Most of our players ply their trade at the very top club level while you can't say the same for Ghana, but that doesn't mean we will underestimate them because we know they are a very good side," he said.
"There are two Ghana internationals at my (Italian) club Udinese, Emmanuel Agyemang-Badu and Kwadwo Asamoah, and Stephen Appiah was also my team mate there before he left so I know exactly how tough they will be to break down."
