The Chiefs have signed Japanese prop Hiroshi Yamashita and Countries flanker Sam Henwood as injury replacements for Neopo Laulala and Mitchell Karpik, who have both suffered season-ending knee injuries.

Yamashit, 30, joins the Chiefs from Japanese club Kebelco Steelers, while Henwood, 24, joins from Portuguese side, Tecnico.

"Sam had an impressive ITM Cup and was unlucky not to be selected for a Super Rugby team. He's been playing in Portugal and is in good nick. Sam is ambitious, professional and excited to test himself at this level," Chiefs' coach David Rennie said.

"Yama is an experienced international prop and has quickly made an impression since his arrival."