Former New Zealand men’s sevens coach Gordon Tietjens believes one lapse in judgement can prove costly for his Samoan side at the Rugby World Cup Sevens tournament in San Francisco.

Tietjens says the Pacific nation has struggled a lot on the world circuit since their 2009 World Series win.

The Samoan coach believes Samoa lacks resources and says they are trying to build depth, particularly on the island, to get them to play the pace of the game that needs to be played on the World Series.

Samoa finished 10th on the World Series tournament this year.

Tietjens coached the New Zealand men’s sevens side from 1994-2016.