The Serbians must avoid defeat against Germany in Port Elizabeth on Friday to stand a realistic chance of advancing to the last 16 and Jovanovic acknowledged it would be a tall order.
"The setback has affected our confidence because we expected to win the game against Ghana and most of us found it difficult to come to terms with the fact that we let ourselves down," Jovanovic told a news conference.
"We lost to a team which is not in our bracket in terms of quality and we now have to make amends against one that is superior, which is going to be very difficult.
"The Germans were as impressive as ever in their 4-0 rout of Australia, they were firing on all cylinders like a well-oiled machine and we'll have to play almost beyond our limits to beat them."
Serbia's coach Radomir Antic is unlikely to make sweeping changes but will have to reshuffle his back four after central defender Aleksandar Lukovic was sent off against the Ghanaians.
He is likely to introduce Neven Subotic, who plays for German side Borussia Dortmund, while midfielder Nenad Milijas could be dropped after a poor performance against Ghana.
Milijas said the busy group stage schedule, leaving no time to lament over early setbacks, could play into Serbia's hands as they brace themselves for the clash with the three-time World Cup winners.
"We have to forget what happened against Ghana as quickly as possible and we should benefit from having to turn our attention to the game ahead, we have to pull our socks up and come out swinging against Germany.
"Hesitation crept into the team during the Ghana game as we struggled to match our qualifying performances and we have to rediscover that form very quickly.
"Germany are obviously the favourites but we are hoping that our trademark defiance and the stinging criticism we took after losing to Ghana will inspire us to better things."
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