The last time Mladen Krstajic worked at a World Cup he was the left-back in a Serbia & Montenegro defence that could only watch as Argentina passed their way to one of the tournament’s great team goals and a 6-0 win. Costa Rica are a notch or two below Esteban Cambiasso and company but on Sunday will be fraught with concerns of a different kind. These days Krstajic orchestrates from the dugout, a green coach seeking to impose order on a nation whose footballing psyche is complex, contradictory and, quite often, self-loathing.

The biggest puzzler is this: somehow Serbia tend to overachieve and wildly underachieve at the same time. Should World Cups be decided on population, the country of seven million would be long gone before the latter stages; offsetting this is the fact that their production line is so accomplished, and talent pool so vast, that their record in tournament football can be described only as abysmal.

Serbia 2018 World Cup team guide: tactics, key players and expert predictions Read more

“My conscience is clear,” Krstajic said yesterday. “I’m honoured to be on the bench at the World Cup. I’m sleeping calmly, you can be sure.”

This will be his fifth match in charge of Serbia and in fact, certainly at senior level, in charge of anyone. His tranquillity appears genuine and, if that transmits to his team, this month then perhaps they will do as they ought: progress from the group stage, as a minimum, and enter the knock-out phase for the first time since they began competing under their modern-day banner.

On paper – which has too often been where Serbia look their best – Krstajic can pick from an enviable cadre. He said he settled on his starting XI for their opening match four or five days ago but would not reveal its composition, suggesting the media might know better than him in any case.

One safe bet is that the Lazio playmaker Sergej Milinkovic-Savic, absent during the qualifiers under Krstajic’s predecessor, Slavoljub Muslin, but a player too good not to be the team’s reference point, will start and, if the patterns forged in last Saturday’s 5-1 friendly win over Bolivia repeat themselves, Serbia will be difficult to repel.

They should entertain, with Dusan Tadic and Adem Ljajic joining Milinkovic-Savic in scheming around the centre-forward Aleksandar Mitrovic. Experience and steel are present, too, in Branislav Ivanovic, Aleksandar Kolarov and Nemanja Matic, but names of a similar stripe have been breathlessly reeled off before without accounting for the fact that composure and cohesion have traditionally been the variables by which Serbia fall short. “I do not see inordinate pressure on them, even though many people want to [apply pressure],” Krstajic said of the generation led by Milinkovic-Savic, who is 23. “They know what to do and are fully focused.”

Should they require a case study of the way in which a healthy measure of concentration and teamwork can turbocharge a team’s hopes, one of the better examples will be lining up opposite them on Sunday night. Costa Rica’s experienced, defence-minded side is the kind that has frustrated Serbia in the past, although they look hard pushed to emulate their last-eight finish of four years ago. Defeats by England (2-0) and Belgium (4-1) offered little sign that anyone will be upset this time; after the latter their coach, Óscar Ramírez, was widely mocked after claiming not to have heard of Eden Hazard, saying: “The No10 did us a lot of damage, I don’t know his name.”

He brought the subsequent ridicule on himself although it might also be viewed as a means of disarming. Costa Rica have succeeded by punching upwards and, if others would rather aim their right hooks in the other direction, then Ramírez will probably not complain. “2014 is over. It is our biggest achievement ever in a World Cup but it is another story,” he said on Saturday, seeking to alleviate pressure by more conventional means. “Our story starts tomorrow with our first match.” Both teams, though, could usefully leaf through the tale they have already written.