The four-time Asian champions bowed to Belarus 1-0 on Tuesday following a 2-0 drubbing by Serbia four days earlier in another away friendly against a country that failed to qualify for the 2014 World Cup in Brazil.

"It is true that we did not play well. But this is not the time to react nervously to one result after another," the Japan Football Association's (JFA) technical director Hiromi Hara said as he returned home with the squad's J-League players.

"We don't intend to change our way of thinking just on the basis of one or two matches," he told reporters at Tokyo's Narita airport, according to Kyodo news agency.

The JFA chief Kuniya Daini said the European results were "not a complete disaster".

"The team struggled but the players just have to keep trying. When we find out what exactly is going wrong we can deal with it," Daini said.

But others have called for the coach to go.

"With the situation as it is now, I think the quickest fix solution is to discharge coach Zaccheroni," popular football commentator Tatsuhito Kaneko wrote in the Sports Nippon daily on Thursday.

After Japan lost three group matches at the Confederations Cup in Brazil in June, the Blue Samurai have changed from "dark horses" to "complete outsiders", said Kaneko.

Japan went down fighting 4-3 against Italy at the tournament of continental champions.

Kaneko blamed Zaccheroni for not changing the first team against Belarus after the stunning defeat by Serbia.

"It seems to me that he was so pressed he had no choice but to play it safe," he said. "Japan became wonderfully strong in the first two years under his guidance. With this in mind, I still feel that the time has come to say goodbye."

Zaccheroni took over the Blue Samurai after they reached the last 16 at the 2010 World Cup in South Africa, led by CSKA Moscow playmaker Keisuke Honda.

They stunned Lionel Messi-led Argentina 1-0 at home in his debut match and won their fourth Asian Cup title in 2011.

The debacle in Europe followed two easy wins over Guatemala and under-strength Ghana and a 4-2 defeat by Uruguay in another home friendly.

Former Japan star striker Kunishige Kamamoto, an adviser to the JFA, said that Japan should follow Asian rivals South Korea and Australia in changing the national coach to bolster their World Cup preparations.

Hong Myung-Bo, a former South Korea captain, replaced another home-grown coach in June. Australia dumped German Holger Osieck as national coach this month following a 6-0 thrashing by France, and are reportedly looking for a local replacement.

"It will be alright if we have a Japanese coach, instead of Zaccheroni, as manager," Kamamoto told the popular tabloid Nikkan Gendai.

He criticised the former AC Milan coach for "automatically" using Europe-based big-name players like Manchester United midfielder Shinji Kagawa and Southampton defender Maya Yoshida, even though they lacked playing time at their clubs.

"Coach Zaccheroni and his players have not achieved anything since they won a berth in the World Cup."