The front-running Crusaders have decided against appealing captain Sam Whitelock's Super Rugby suspension and will take on the Bulls on Saturday without two senior All Blacks.
In addition to losing Whitelock, who copped a two-week ban for striking an opponent during last week's 48-21 win over the Cheetahs, the Crusaders will also be without All Blacks' captain Kieran Read, who broke a thumb in the same match.
The loss of the veteran internationals for round 11 will impact on the Crusaders' pack against the renowned power of the Bulls' forwards.
With the Crusaders the only unbeaten side in the competition after 10 rounds, coach Scott Robertson said after Whitelock's suspension that they were considering an appeal.
However, a team spokesman confirmed to AFP on Thursday they had decided to accept the judiciary's ruling and Matt Todd would take over the leadership.
The Bulls have not enjoyed the best of seasons, with only three wins so far, but two of them have been in their last two games.
They also have homeground advantage, having beaten the Crusaders for the last five times they met in Pretoria dating back to 2008, and coach Nollis Marais said the team was entering this contest with a lot of self-belief.
"The last two wins confirmed that we can indeed compete against anyone," Marais said.
"We have a massive hurdle to overcome on Saturday though, as the Crusaders have been setting a number of benchmarks to other teams this year.
"They remain a classy side and despite not having Sam Whitelock and Kieran Read available for this match, remains one of the top teams in the competition."
Poised to hit the top spot should the Crusaders fall are the Lions, the Africa 2 conference leaders, who are in Melbourne to play the struggling Rebels.
Read's broken thumb, which puts him in a race against time to be fit again for the June Test series against the British and Irish Lions tour, added to the All Blacks' injury woes.
The injury concerns had worsened this week with news that Dane Coles, initially sidelined with a knee injury, now had concussion.
For weeks, the defending champions Wellington Hurricanes have explained the absence of their hooker and captain as down to a struggle to overcome a calf problem.
"Subsequent to his knee injury, he not only developed a calf strain but also some headaches," coach Chris Boyd said when Coles' name was missing from the team-sheet for Friday's clash with the Western Stormers.
"He is now under a return-to-play protocol for concussion."
The Stormers still lead the Africa 1 conference despite losing their past three games and coach Robbie Fleck has said it was time to arrest the slide.
"We have had to learn some hard lessons on this tour which will be good for us going forward," he said.
"We face the defending champions and the players are determined to make an impression."
While the ACT Brumbies have a bye, the NSW Waratahs have a chance to move to the top of the Australian conference.
But to do that they will have to be the first Australian side to beat a New Zealand team this year, and with a bonus point, when they host the Auckland Blues.