Australia fast bowler Mitchell Johnson is expected to be ruled out for five months after being told that he needs to undergo surgery on his toe.

The 30-year-old, who picked up the injury during a batting innings in Australia's win over South Africa, has been monitored by specialists.

"Mitchell will travel to Melbourne this week to be reviewed by specialist doctors and will most likely need surgery, which is expected to keep him out of cricket for four to five months," said national team physiotherapist Alex Kountouris.

"The programme for his recovery will be assessed following any surgery."

The bowler will miss the second Test against New Zealand if the operation goes ahead.