Croatia midfielder Ivan Rakitic has hailed the otherworldly talents of Luka Modric and Andres Iniesta.

Barcelona's Rakitic and Real Madrid's Modric have resumed their esteemed midfield alliance for Croatia at the 2018 World Cup to superb effect, with Zlatko Dalic's side one of only three to progress through the group stages in Russia with a 100 per cent record.

Iniesta has signed off on his decorated Barca career but remains a key part of Spain's bid for glory before he begins a news chapter in Japan with Vissel Kobe.

Should they come through respective last-16 matches against Denmark and Russia, Croatia and Spain will meet in the quarter-finals and Rakitic has no doubt it would be a meeting of the very best.

"It's very difficult to compare them. It seems like both of them are from different planets and they came to play football with us mortals here," Rakitic told a news conference at Croatia's Roschino base.

"Both of them are among the best players ever in their positions. It has been a great honour to play with Andres in the last four years at Barcelona and with Luka for the last 11 years for Croatia.

"You try to enjoy it as much as you can, to learn from them. It's the best thing that can happen to any player. If I created a football team, I would have both of them in my team.

"I can thank God to have the opportunity to play with both of them. Hopefully with Luka I am not done yet; unfortunately Andres is not with Barcelona anymore but I wIsh him all the best.

"They are both more than team-mates for me. Andres is one of my best friends and I see Luka as my big brother."

Croatia great Robert Prosinecki recently said four-time Champions League winner Modric had surpassed him as his nation's greatest ever player and Rakitic is not about to disagree.

"I would agree with him completely," he said. "Not only that Luka is the best player, but he is a great person, a leader and we are following him."

Modric and Rakitic head a sublime generation of Croatian talent who first came to prominence at Euro 2008, with Russia 2018 seemingly their last chance to make a defining impact on the biggest stage.

"I don't know if this is the last competition for us, we will see about that. But, in any case, we would like to continue the same way we have been playing so far," Rakitic added.

"We have a great atmosphere in the team. We are fighting for each other, that is our strength. We want to continue on that same path.

"Of course, the game against Denmark is in front of us. We are taking it step by step. If we at the end manage to lift this trophy, we go into international retirement happy."