Croatia's Nikola Vlasic (left) fights for the ball with Canada's Alphonso Davies during the World Cup Group F soccer match between Croatia and Canada, at the Khalifa International Stadium in Doha, Qatar, Nov 27, 2022. (THANASSIA STAVRAKIS / AP)

DOHA - Croatia were as surprised as anyone by Japan's group-stage wins over former champions Germany and Spain at the World Cup, but while they will not underestimate their last-16 opponents on Monday they also feel ready to handle the Asians' need for speed.

Japan opened their group matches with a stunning come-from-behind win over four-time world champions Germany and went on to secure qualification with another comeback victory by the same score over 2010 World Cup winners Spain.

I think hardly anyone expected that, but hats off to Japan ... They showed that it is not names that are playing, but what is more important is heart and courage. They deserved this and showed their quality.

Lovro Majer, Croatia midfielder

Despite having very little possession, with just 17 percent against Spain and 26 percent against the Germans, they emerged victorious in both games.

"We did not expect this," Croatia midfielder Lovro Majer said on Saturday. "I think hardly anyone expected that, but hats off to Japan."

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"They showed that it is not names that are playing, but what is more important is heart and courage. They deserved this and showed their quality."

Croatia, runners-up in 2018, may be the favorites, but Majer said the number of major upsets so far in this competition should act as a warning.

"If you underestimate someone today it will come back to bite you," he said. "Everybody is playing good football. We have seen many surprises at this World Cup."

"I think overall the football being played here is magnificent. One of the key reasons is because it is in the middle of the season where everybody is in top shape."

Croatia have a perfect Round of 16 record at World Cups, having never lost their first knockout game when making it out of their group in five visits to the World Cup finals.

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While they have not been as dominant in the group stage this time as four years ago, they did enough to get through with two draws and a win, and fatigue is not an issue.

Croatia have a perfect Round of 16 record at World Cups, having never lost their first knockout game when making it out of their group in five visits to the World Cup finals

"My tank is full," said Croatia defender Josip Juranovic, a starter in all three of their group games. "This is the World Cup and it may only come once in your career."

"When you see (37-year-old Luka) Modric sprint in the 89th minute then you get motivated to run as well. We are all in top shape in mid-season."

As for the Japanese side's speed that proved lethal against Spain and Germany, Juranovic said their own 4-1 comeback win over Canada, another fast team, had helped prepare them for Japan.

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"Possession means nothing in football today," he said. "They play very well as a team and they are fast. We showed against Canada we can deal with quick teams."