New Zealand. Two words and one country guaranteed to set Marko Grujic waxing lyrical. "The 30 days I had there," he told FIFA.com, "were probably the best of my life."

Plenty of awed tourists have said the same. But while those visitors tend to revel in the spectacular scenery, Grujic saw next to nothing of the mountains, lakes and forests for which this island nation is famous. His month in New Zealand was instead spent rotating between training grounds, stadiums and hotel rooms, a monotonous routine the Serbia midfielder now remembers now as sheer bliss. What is sightseeing, after all, compared to making history.

That was what Grujic and his team-mates, against all odds, succeeded in achieving during their magical month Down Under. Their Herculean efforts brought Serbia a first, wholly unexpected world title, secured in style with a thrilling final win over Brazil.

"It was unbelievable," recalled Grujic. "I'd dreamed that one day we could win a big tournament like that. But the whole thing, and beating Brazil in the final, was just fantastic. It's a time in my life I know I'll never forget."

It was an impossibly dramatic 118th-minute goal that put paid to the Brazilians, and there could not have been a more fitting climax to Serbia's campaign. Theirs, after all, had been a triumph achieved the hard way. Not one of the champions' four knockout matches were settled within 90 minutes, and they had been seconds from crashing out to Hungary in the last 16 before going on to win with ten men.

"All those games were tight, but I remember always feeling sure that we would win," said Grujic. "And we scored so often in the last few minutes that you almost began to expect it. We never gave up, we always felt we could score, and that continued to the final and the extra-time goal that won it for us."

The remarkable frequency of such feats led Serbia's proud coach, Veljko Paunovic, to boast of having a squad of "21 lions". Yet Grujic insists that Paunovic himself should take huge credit for the never-say-die spirit that underpinned their success.

"What helped us a lot during the tough times was that our coach was great - a very nice guy," said the Liverpool midfielder. "He had such huge passion and always tried to share that with us, and it really worked. The players were also great friends away from the pitch and that's where a lot of our strength came from. What you saw on the pitch came from the bond we had, and the result was the best performance our country has ever had in a football tournament.

"The players from that team still stay in touch. Many of the guys I still see playing for the U-21s and the senior team and we still speak about New Zealand. A lot of the players have also made moves to Italy, Germany and other big teams, and it's been nice to see your friends succeeding like that."

We scored so often in the last few minutes that you almost began to expect it. We never gave up.

Marko Grujic

Before they began to switch clubs, those players were first treated to a heroes' homecoming, when over 50,000 chanting, flare-waving fans roared their appreciation at a packed Belgrade square. However, those same passionate supporters have enjoyed considerably less to cheer about with their senior side of late, and this has damaged the relationship between team and fans.

"There is big pressure on the national side right now from our supporters because we didn't qualify for EURO 2016 or the last World Cup," admitted Grujic, who broke through to the senior side earlier this year. "There is a lot of negativity and some people in the country have stopped believing in the national team. The only way to stop that is to make sure we start winning again."

Inevitably, given the success of Grujic and Co in New Zealand, there have been widespread calls for the country's U-20 heroes to be promoted en masse. But the Liverpool midfielder is in favour of a more measured approach to tackling Serbia's problems. "So many people are calling for that: 'Get the boys from from New Zealand in the senior team'," he said. "But I don't think that's 100 per cent the answer because a team with only young players, still learning, can't be expected to get results immediately. Many of the players from that team can help the senior side, but we also need the older, experienced guys to help us too."

Striking the right balance will need to be done quickly, though, as Serbia are already under pressure in FIFA World Cup™ qualifying. Dropping points at home to Republic of Ireland in their opening match represented an unconvincing start, and though they bounced back with a 3-0 win against Moldova last night, Sunday's showdown with Austria is sure to offer another stern examination of their credentials. Nonetheless, Grujic is confident of them reaching Russia 2018.

"It's an interesting group, with lots of teams at a similar level, and I think we have a good chance to qualify," he said. "Wales had a fantastic EURO of course, and Austria and Republic of Ireland also went to France and are very strong opponents. But there is no-one there we can't beat."

Grujic is similarly positive about his future at club level, having turned down several of Europe's biggest clubs earlier this year to sign for English giants Liverpool. Jurgen Klopp certainly appears to have big plans for a youngster he recently lauded as a "wonderfully skilled player", while the midfielder, for his part, has embraced the German coach's all-action ethos and advice on addressing his shortcomings.

"The big thing the coach said to me was that I needed to improve my defensive attributes," said Grujic. "I'm trying hard to do that and I know that I'm still young, learning all the time and still adapting to English football. At Liverpool, we play very high on the pitch with a lot of running and pressing. I saw the statistics and we are top in England in terms of the amount of metres we run in a match. It's a great philosophy and working well for us, but it's tough too and takes some time to adapt to be perfect in it.

"I love to learn and improve though and I'm definitely very happy with my choice of club. The atmosphere around Liverpool is great right now and I just want to get more and more minutes on the field to show my skills."