Habana was on Thursday excluded from a 12-man South Africa Sevens squad, the veteran winger overlooked as coach Neil Powell opted for Juan de Jongh and Cheslin Kolbe from his 15-a-side contenders.
Habana has won a World Cup and a southern hemisphere title with the Springboks, and also southern hemisphere and European club titles.
Habana added that the squad was in good shape to challenge for gold in Rio. The Australian women's team, a mix-and-match ensemble of athletes from other sports, enters the Olympic sevens tournament as world champions, a rare achievement in a series previously ruled by New Zealand.
"I'll be your biggest supporter and cheering you on loudly from Toulon!"
It has been a tough season for the men's sevens squad.
Stormers captain Juan de Jongh was the only Bok who did it enough to earn the nod from Powell, while Hougaard is one of two reserves - with Chris Dry - who will travel with the team to Rio, which will be led by Kyle Brown.
The Australian men are ranked fourth in the world, but the women are number one after winning the Rugby Sevens World Series this year in dominant fashion. "We will focus on what we do well and that will hopefully bring the desired results".
The Blitzboks have been drawn in Pool B alongside Australia, France and Spain, with the Olympic tournament taking place from August 9-11.
Nick Cummins and Henry Speight both suffered injuries which curtailed their chances, while Habana's Toulon teammate Quade Cooper was ruled out in May.
The former Australia rugby league star cut short his NFL contract to join up with Fiji for May's series finale in London, but he has not made it to the last week of the team's selection camp.