Chiefs back-row Michael Leitch will be out of action for eight to 10 weeks after dislocating his thumb in his side's win over the Rebels at the weekend.
Leitch went for an x-ray on his injury and the results revealed that he is set for a lengthy spell on the sidelines which could ultimately mean he has played his last match for the two-time champions this year.
The Chiefs' last regular season match is against the Highlanders in Dunedin on July 16 which is eight weeks from the time of the injury. This means that a possible return to action for the 27-year-old will only be during the tournament's knockout stages.
Leitch's injury also rules him out of Japan's upcoming Tests away to Canada and at home against Scotland. His injury is a massive setback for the Chiefs, who take on the Waratahs in Sydney on Friday.
With Leitch sidelined, Maama Vaipulu is set to replace him in the Chiefs' squad for the clash with the 2014 champions.