Vernon Philander believes Australia captain Steve Smith is "just as guilty" as Kagiso Rabada for the incident which led to the South Africa paceman's suspension.

Rabada was given a two-match ban for making inappropriate and deliberate physical contact with Smith after dismissing the batsman in the second Test.

The speedster is appealing the suspension, which would rule him out for the rest of a series currently locked at 1-1.

But Philander questioned Smith's role in the incident, saying the 28-year-old could have avoided contact.

"Havent [sic] really seen the fotage [sic] of this incident but by the looks of this...Steve Smith gave KG the shoulder," he wrote on Twitter, alongside a video of the incident.

"He could have avoided any contact but to me he is just as guilty.

"Trying some football skills to get a penalty??? Pity he didnt [sic] dive to top it off."

The third Test of the series starts in Cape Town on March 22.