4Scotland's John Hardie (R) tackles Japan's prop Hiroshi Yamashita during a Pool B match of the 2015 Rugby World Cup between Scotland and Japan at Kingsholm stadium in Gloucester, west England on September 23, 2015. AFP PHOTO / LOIC VENANCE RESTRICTED TO EDITORIAL USE, NO USE IN LIVE MATCH TRACKING SERVICES, TO BE USED AS NON-SEQUENTIAL STILLS (Photo credit should read LOIC VENANCE/AFP/Getty Images)

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."