Embattled Honda surprised partners McLaren on Tuesday by announcing a change of leadership in their Formula One engine program less than a month before the season starts in Australia.

The Japanese company said Yasuhisa Arai, the boss who managed to keep smiling through the team's worst ­season last year, will step down at the end of the month and be replaced by Yusuke Hasegawa.

Honda press officers said the team had been informed only after a statement detailing a wider management restructuring of Japan's third-largest carmaker was issued by company headquarters on Tuesday.

The move was aimed at bringing youth and diversity to the management team.

Hasegawa has previous experience in Formula One from Honda's time with the BAR and Jordan teams in the 1990s and 2000s.

"I need to catch up with what is going on," Hasegawa told Reuters during testing at Barcelona's Circuit de Catalunya.

"There are a lot of good people working very closely with McLaren so I don't think it will be a big problem.

"Compared to Arai, I think I am a very conservative person."

Arai's optimism seemed at odds with the reality at times last season as McLaren endured record grid penalties because of repeated engine failures. ­Media reports suggested that the former champions wanted him replaced.

Last season was the first of Honda's new partnership with McLaren, who have not won a race since 2012 and ­finished ninth of 10 teams.

Arai, who will retire next year, told Reuters he would help Hasegawa settle in for as long as he deemed necessary before stepping aside completely.

"I will do my best to support him," he said. "He has a different personality, the approach is a little bit different. This year we know how big the gap is to the top teams ... so we don't say such optimistic words. More realism."

In a joking reference to a photograph of McLaren driver Fernando Alonso that went viral on social media last season, the departing boss said he looked forward to sunning himself on a beach in a deckchair when retired.

When Alonso's Honda engine failed in Brazilian Grand Prix practice last year, the Spaniard found a foldable chair and lay back trackside sunning himself with his feet resting on his helmet.

The picture swiftly spread around Twitter with fans imagining other places Alonso would rather be.