Brian O'Driscoll and Jamie Roberts team up again at centre for the British and Irish Lions against the Sharks in Durban on Wednesday.
They were outstanding in the 74-10 win over the Golden Lions last Wednesday.
Lee Byrne, Shane Williams, Luke Fitzgerald and skipper Paul O'Connell survive from Saturday's 26-24 defeat of the Free State Cheetahs.
"The next two matches are obviously critical in the development of the Test side," said coach Ian McGeechan.
O'Connell, Byrne, Shane Williams, Roberts and David Wallace will all be making their third appearances of the tour.
O'Connell will pack down with his third different partner in the second row, lining up alongside Wales' Alun Wyn Jones.
Martyn Williams is the only member of the squad unavailable for selection but Lions doctor James Robson expects the Wales flanker to recover from a shoulder problem in time for the weekend.
England centre Riki Flutey has been included on the bench after recovering from a knee injury which almost forced him off the tour.
The Lions are also trying new starting combinations in the half-backs, where Mike Phillips will link up with Ronan O'Gara, and in the front row, with Lee Mears hooking between Welsh props Adam Jones and Gethin Jenkins.
The Sharks give full-back Stefan Terblanche the chance to take on former Ospreys team-mates such as Byrne and Shane Williams.
The hosts also include prop Deon Carstens, who has been released from the Springboks' training camp for the encounter.
Carstens was released along with Ryan Kankowski and Odwa Ndungane, but the latter duo were not considered because of injury.
Lions boss Ian McGeechan
McGeechan said: "I am delighted that as we head into the fourth match we only have one player who is unavailable for selection.
"The players and the medical staff have managed the injuries that have been sustained in a very professional manner.
"This is crucial as we enter matches against two of South Africa's strongest provinces in the Sharks and Western Province in the space of four days.
"This is reflected by the fact that four starting players from the Cheetahs match will back up against the Sharks, while five players are starting their third match of the tour.
"We also have new starting partnerships in the back three, the half-backs and in the front row.
Jamie Heaslip, Wallace and Tom Croft also played together against the Golden Lions.
Tour manager Gerald Davies said: "We are now halfway through the provincial matches prior to the first Test and the important factor is that the Lions are unbeaten."