South Africa’s Robin Peterson called Shane Watson’s calf injury an immense blow to Australia’s hopes of starting the three-Test series on a high note.

Shaun Marsh arrived in Johannesburg early on Sunday, when the squad enjoyed a rest day and selectors pondered the best way to replace Watson in the XI.

Peterson, speaking after the Proteas’ training session on Sunday at Centurion, gave an honest appraisal of Watson’s value to the Australian team.

“Shane is a quality cricketer, a guy who can take the game away from you with bat or ball,” Peterson said.

“He’s had reasonable success in South Africa with the ball and with the bat, so he’ll be a massive loss for them.

“But whoever they replace him with (should be capable).”

Australia will train on Monday and Tuesday before the first Test starts at Centurion on Wednesday.

Alex Doolan is expected to bat at first drop in a reshuffled order, with Marsh, Phillip Hughes and Moises Henriques battling for the other berth.

Peterson was adamant Watson’s replacement would be a clear-cut decision for coach Darren Lehmann and chief selector John Inverarity.

“They’ll probably go for the allrounder (Henriques). It’s the only option,” Peterson said.

“You don’t want to leave yourself short in South Africa, only having three seam bowling options. If one breaks down you’re stuck with two.”

Peterson played down the destabilising effect of having two new faces in an XI that went unchanged throughout a 5-0 Ashes sweep of England.

“It’s happened to South Africa plenty before, and we’ve come out on top. So I wouldn’t see it any different for Australia,” he said.