Another midfield back, Tamati Ellison, has undergone shoulder surgery and is out for the game for some months.
Liam Messam is the incumbent test blindside flanker and was a key member in the Chiefs' success last season.
He has played 20 tests but even with that experience and his range of skills he has not convinced me he is a test regular.
Perhaps he is taking the sort of journey which Jerome Kaino did, before he became indispensable for the All Blacks.
If so, great. In the meantime, centre and blindside have the Vacancy sign hovering over them.
Ben Smith may be the man for the No13 jersey but it would help if he played there for the Highlanders and became used to the partnership with Ma'a Nonu.
If powerhouses Rene Ranger and Robbie Fruean sort out their impact and consistent defence, they must swing into the limelight.
There will be theories too that Nonu could play centre if the selectors are tempted again by a twin five-eighths scheme with Daniel Carter moving into the No12 jersey.
That works against some teams but looks, like ideas about Tom Taylor or Frances Saili as understudies, to be the least likely decision.
Thomson's departure should say, "Over to you Messam and Victor Vito."
Both players have huge talent but have been slow to boil, consistently. Their joust looms as a tasty selection development for the June tests against France.
Others pushing for that role should be Brad Shields, perhaps Jarrad Hoeata or Luke Braid.
Come Rugby Championship time a familiar name and a well-worn theme should emerge.
Richie McCaw, the 116 times capped All Black captain, plans to return to the test stage after his time out.
If Sam Cane has played his ears off as an openside against France and there have been mixed blindside displays, the selectors will dust off their twin flanker dossier.
McCaw fits the physical bill for blindside. He is a brutal defender with a massive workrate, strong over the ball without being the most fluent in possession.
His sabbatical and player developments could persuade McCaw and the selectors this is a great time for a rethink and new direction in the push to the 2015 World Cup.