What was originally suspected as a knee contusion and haematoma suffered against the Blues was revealed after a scan as a significant tear. As a result, he will see a specialist with a worst-case scenario suggesting he could be out for eight to 12 weeks.
Since the World Cup Ta'avao had been in the medical wars having had an Achilles tendon problem that required an injection while he also needed to have a cauliflower ear drained.
Chiefs coach Warren Gatland said flanker Luke Jacobson had suffered a hamstring injury early in the Brumbies game.
It was not as bad as first thought and it was a case of getting him back into training. It was something that didn't affect his running but came out when mauling and scrummaging was involved and it would be a case of managing that workload in his recovery.
Although the Chiefs have a bye this week that wouldn't be enough time to have Jacobson ready for the Waratahs game next week.
One more positive note was that another All Blacks prop Nepo Laulala was due to return to training next week.
In their post-game discussion after their first loss of the season, to the Brumbies in Hamilton on Saturday, the Chiefs had been disappointed with the way they started again and have looked at ways of addressing that through their warm-ups and their mental focus ahead of games.
"We were disappointed. The thing about this tournament though is it is pretty hard to go through this tournament unbeaten. We got a Brumbies team that played as good as I've ever seen them play. They were pretty accurate," Gatland said.
"The pleasing thing for us, we've looked at first-half stats and second-half stats and we've been strong in all four games in the second half and we've dominated the second half.
"That shows me we're in pretty good shape physically and we're in a pretty good space mentally and these boys are not prepared to chuck in the towel. They want to fight to the very end so we've just got to make sure we're not behind on the scoreboard in a few of those games.
"We've spoken about what a good place we're in, we don't need to reinvent the wheel, we've just got to tidy up on a few things. We've spoken about the penalties and turnovers in the first half. They were costly but there are definitely some positives in the second half and for me, it's about tidying up on the two or three things maximum that we can tidy up from last week and if we can do that we will really improve our performance," he said.