It is a short turnaround for the Chiefs, who played yesterday morning NZT and will arrive home from South Africa only tomorrow morning (Mon) after a journey of 30 hours.
Anti jet lag measures will be taken, but there are still sure to be some sleepless nights for Rennie's players, who lost narrowly to the Stormers and beat the Southern Kings during their trip.
Rennie will be without No8 Ross Filipo, who injured his knee in his first game for the Chiefs and now faces a long stretch of rehabilitation from an ACL injury. "It's a long-term injury," said Rennie. "It's really gut-wrenching for him. He's had an elbow injury and he got his first crack only for this to happen."
Other players are beaten up. Liam Messam, who celebrated his 100th game for the Chiefs in the 35-24 victory at Port Elizabeth, injured an ankle in a tackle late in the match and the joint was badly swollen after the match.
"Hopefully it won't amount to much," Rennie said.
On the positive side of things, lock Brodie Retallick's hip injury stood up well - he entered the match from the reserves bench after not being able to train all week - and Sam Cane suffered no ill effects from the stitches in an ear put in after the Stormers match in Cape Town.
Rennie is expecting a "desperate" Highlanders at Waikato Stadium as Joseph's men continue their search for a first win of the season.
However, their style shouldn't come as a surprise.
"We've played them twice already this year, unbelievably," said Rennie. The Chiefs beat the Highlanders in a pre-season match in Taupo and accounted for them 41-27 in their first competition game of the season in Dunedin.
"We'll have to be a hell of a lot better than we were [against Kings]," he said.
One particular area of concern will be the breakdown, where the Chiefs were again heavily penalised and lost replacement halfback Augustine Pulu to the sinbin in the second half. The week prior they lost both Tawera Kerr-Barlow and Nick Crosswell to the bin.
"It's a major concern," Rennie said. "We seem to be counter-rucking okay, but as soon as we put our hands in we are getting penalised. Smithy [assistant coach Wayne Smith] has done a lot of work in that area and it's disappointing."
The Kings, who lost lock and captain Darron Nell before kick-off with a calf injury, scrapped and scrambled, but looked vulnerable when the Chiefs spread the ball.
Lelia Masaga, sporting a cut on his left cheek, cashed in with three tries; flanker Sam Cane, who replaced Filipo, scoring the other in the second half when bulldozing over from close range.
The Kings' 18-year-old speedster Sergeal Pietersen, scored a popular 90m try just before halftime when capitalising on a misunderstanding between Aaron Cruden and Masaga, and No8 Jacques Englebrecht dived over from close range after Pulu's departure.
The new kids on the block came closer to the Chiefs than was expected, which annoyed Rennie, but although he was disappointed with aspects of their win and narrow loss in Cape Town, where they got two bonus points, seven points from two games is a good haul in the Republic.
Chiefs 35 (Lelia Masaga 3, Sam Cane tries; Gareth Anscombe 3 cons, 3 pens).
Kings 24 (Sergeal Pietersen, Jacques Englebrecht tries; Demetri Catrakilis con, 4 pens).
HT: 18-13.
