Richie McCaw still faces a fitness test but All Blacks assistant coach Ian Foster is confident the veteran captain will be cleared to play the Rugby Championship decider against South Africa in Johannesburg.

McCaw, 32, sustained a knee injury against Argentina on Hamilton on September 7 and has missed subsequent wins over South Africa in Auckland and the 33-15 defeat of Argentina in La Plata last weekend.

The World Cup winning skipper always targeted the Test at Ellis Park on Sunday for a return and Foster says McCaw is likely to earn his 120th cap, replacing Sam Cane on the openside flank.

“Richie has done really well, and he put in a great week of hard preparation in Argentina last week,” Foster said.

“We still have to get him through a few runs that will test his readiness, but I would say that he more than likely will play.”

McCaw has never played at Ellis Park, a venue where the All Blacks traditionally struggle.

They haven’t been back since a loss in 2004. Two subsequent visits to Johannesburg have been for Tests in Soweto, where the All Blacks won in 2010 and 2012.

Springboks forward coach Johan van Graan acknowledged McCaw’s influence but says they aren’t spending time focusing on the player who has lodged just 239 minutes of total playing time this year.

“Richie is one of the all-time best players, we respect him for that but we’re just going to focus on what we want to do,” van Graan said.

“They have 15 world class players in their team. I think Sam Cane and (blindside flanker) Liam Messam played brilliantly in Auckland and even though Richie McCaw is back and is captain again, it won’t influence us.”

Van Graan says the Springboks have improved considerably in their breakdown play this year, a major factor in winning seven of eight Tests.

Meanwhile, Foster delivered some positive news on the fitness of prop Owen Franks, who was replaced at halftime in La Plata after sustaining a groin injury.

The 51-Test tighthead had been comfortable on the All Blacks’ 12-hour flight from Argentina and progress on the injury has been impressive, Foster said.

If he is deemed unfit, Franks’ No.3 jersey will be handed to Charlie Faumuina, who impressed against the Pumas.