By Jack Tarrant
SAMARA, Russia (Reuters) - Serbian coach Mladen Krstajic dismissed fears that his lack of experience as manager of the national team could hinder their chances against Costa Rica in their World Cup opener on Sunday.
Krstajic, who had no club coaching experience when he took over the national team in October, will be taking charge of his first competitive game against the Central Americans in Samara.
However, the 44-year-old says he is confident in his side's preparations and will be leaning on some of his more senior players to lead the way.
"As far as this story about me lacking experience, I don't have any problem because I am working with professional players who prove themselves in clubs across Europe," Krstajic told reporters on Saturday.
"My conscience is clear because we are working really well and have been together for three weeks. These are things that make me happy.
"We have to be focused, responsible. When I met my squad for the first time I said lets relax, be friends off the pitch, but when comes to matches everyone has to be responsible."
The most experienced player he can call upon is defender Branislav Ivanovic, who could become Serbia's most capped player on Sunday with 104 international appearances.
The Zenit St Petersburg player, who won the 2012 Champions League with Chelsea, will likely be joined by captain Alexander Kolarov in a mature backline.
"God willing, he is going to break the record," said Krstajic.
"He has demonstrated his qualities in different clubs around Europe and has won many titles. This provides us with extra motivation to give more and we want to make his day tomorrow better."
"He has brought us so much," added Kolarov, who has 76 caps for Serbia himself.
"Hopefully nobody breaks his record. We are all happy for him."
With Brazil overwhelming favourites to top Group E, which also includes Switzerland, a win in the opening game would go a long way to securing qualification to the last-16.
However, Kolarov knows the following match against Switzerland could be the most decisive in a tight race for second.
"Of course the upcoming game is the most important in several years. Tomorrow's game will show how important the subsequent games will be. Whatever the score, whatever the result, Switzerland is going to be the key for our qualification.
"I hope that we will get a good result and it will mean a lot to us if we do win tomorrow."
Krstajic, who is likely to field a 4-2-3-1 formation with Aleksandar Mitrovic as the lone striker, says he has been certain of his starting line-up for the past five days.
(Reporting by Jack Tarrant; Editing by Christian Radnedge)