Sunwolves coach Mark Hammett was on Thursday named as one of two interim coaches for upcoming Japan national team matches, deputizing for incoming Brave Blossoms' coach and fellow Kiwi Jamie Joseph, who is unavailable due to commitments with his Highlanders Super Rugby team.

Hammett takes control for three full test matches in June, one to be played in Canada and two others against Scotland in Japan, while Ryuji Nakatake has been tapped to manage the team's four Asian Championship matches against South Korea and Hong Kong in April and May.

"I am happy to be able to support Japanese Rugby as the interim head coach for the Cherry Blossoms for our June test matches against Canada and Scotland," Hammett said in a press release.

"My aim is that we are competitive in our three June test matches and that our management group hand over a successful team to new head coach Jamie Joseph."

The Japan Rugby Football Union's director of rugby, Masahiro Kunda, has recommended that the core of Hammett's squad should come from Japan's overachieving Rugby World Cup 2015 group, with Michael Leitch continuing in the role of captain.

Nakatake, however, will coach a team largely made up of under-20 players with a few overage players sprinkled across the pitch. The JRFU's coaching director, Nakatake is currently in Fiji coaching the Junior Japan team in the World Rugby Pacific Rugby Challenge, and he will likely see a lot of overlap between that squad and Japan's Asian Championship team.

Japan fielding an under-strength team for the games against Hong Kong and South Korea could be a concern as the matches were recently given designation as full test matches, with world rankings points on the line. The Brave Blossoms will be hoping their underage players can perform well against their lower-ranked opponents from Asia.

Joseph is scheduled to take up his role with the Brave Blossoms in Japan in August or September as he remains unavailable while piloting his Highlanders in their Super Rugby title defense. Hammett, it seems, was able to find time in his own tough Super Rugby schedule, knowing the importance of Japan's rugby fortunes with an eye on the 2019 World Cup.

Japan's first Asian Championship match is against South Korea on April 30 in Kanagawa. The team will then take on Hong Kong away on May 7, South Korea away on May 21 and Hong Kong on May 28 in Tokyo.

On June 11, the Brave Blossoms will face Canada in Vancouver before returning home for two matches against Scotland, on June 18 and June 25.