Whitelock damaged his calf at training and is on the way back to New Zealand, following in the footsteps of Liam Squire, who broke his thumb last week in the win over the Cheetahs.
It has been a tough year for Whitelock as he picked up a shoulder injury in the pre-season which delayed his start to the season.
He then suffered a concussion in the game against the Sunwolves and, although he saw that game out, he was forced to miss the following week against the Stormers.
With Whitelock and Squire — the two leading No8 candidates — both out, the versatile Gareth Evans has slotted into that position.He will be joined by Dillon Hunt on the openside with Elliot Dixon getting a start on the blindside flank.
Tupua Sopoaga is flying over to join the side but the loose forward cover on the bench will be provided by Jackson Hemopo and Joe Wheeler as the Highlanders have only three fit loose forwards.
Dan Pryor and Shane Christie have not been sighted all season while James Lentjes lasted just one minute into the second game of the season before dislocating his elbow.
Dixon started from the bench last week after missing the past two games because of a knee infection.
Hooker Ash Dixon gets his first start and will also captain the side. Liam Coltman will have a complete rest allowing Greg Pleasants-Tate to be the reserve hooker.
Alongside Dixon in the front row is Aki Seiuli, who gets a start with Daniel Lienert-Brown moved to the bench. Lock Alex Ainley comes into the side with Wheeler moved to the bench.In the backs, Richard Buckman slots in at second five-eighth instead of Rob Thompson.
It is a tough call for Thompson, who has played well of late but Buckman is a class footballer who has missed the past two games because of a strained Achilles.
Matt Faddes continues at fullback while Tei Walden comes on to the bench.
The Bulls are under pressure and received further bad news during the week when flanker Jacques Potgeiter was ruled out of the match because of blood pressure. Winger Travis Ismaiel is out for six weeks with a knee injury.