Tana Umaga has resigned as Auckland Blues coach. Photo: Brendon Ratnayake / www.photosport.nz

WELLINGTON – All Blacks great Tana Umaga stepped down as head coach of the Auckland Blues on Thursday after disappointing results during his three years in charge of the Super Rugby club.

Umaga will remain with the Blues as defence coach but hand over the top job to Leon MacDonald, who was originally brought in as Umaga's assistant last May.

The Blues ended the regular season at the bottom of the New Zealand conference for the third-straight year and have not made the playoffs since 2011.

Team officials raised eyebrows in May when they gave Umaga another year in charge.

But they said Monday that a review of the 2018 campaign, which yielded just four wins, had underscored the need for a change in head coach.

Umaga will remain with the Blues as defence coach but hand over the top job to assistant Leon MacDonald. Photo: Chris Ricco/BackpagePix
Umaga will remain with the Blues as defence coach but hand over the top job to assistant Leon MacDonald. Photo: Chris Ricco/BackpagePix

Blues chief executive Michael Redman acknowledged the Blues was "a challenging environment" but said the club wanted to keep Umaga on to maintain continuity, rather than starting afresh with a new coaching team.

"Tana has a tremendous amount to contribute on the grass and he has learned a lot about this team," Redman said. "He can still apply this experience in his new role, which will greatly assist Leon as new head coach."

The Blues, representing New Zealand's biggest city, were once a rugby powerhouse but claimed the last of their three titles in 2003.

Despite having the largest talent pool in New Zealand, they have developed a reputation for allowing promising youngsters to slip through their fingers and failing to make the most of those who do stay.

MacDonald, a 56-Test fullback, said he was determined to make a difference at the Blues.

"I am highly motivated to help the Blues' vision for success... I will give it my heart and soul," he said.

Agence France-Presse (AFP)