The 28-year-old Delhi batsman was dumped from the national side for the current England tour after the team's shock first round one-day World Cup exit in March that followed a personal string of low scores.
India's only batsman with a triple-hundred in Test cricket is hoping to display his touch ahead of a busy period for the national side that includes home series against Australia and Pakistan followed by the tour Down Under.
Hosted by South Africa, the inaugural Twenty20 event will run from Sept 11-24.
''Twenty20 is new format and it suits my type of batting. I am working on my batting and fitness. If I do well in South Africa I have the chance to make a comeback in the ODI team,'' Sehwag said.
"We played (a Twenty20 game) in South Africa last year and we beat them when I was captain."
''I have toured South Africa three or four times and I know the conditions there. So, I think I should do well there.'' The 28-year-old batsman was all praise for Mahendra Singh Dhoni, India's captain for the Twenty20 World Cup.
''Dhoni getting the captaincy is good for India. He is maturing and has a great cricketing brain. I hope he will do well,'' Sehwag said.
Sehwag made his comments at a ceremony to unveil the Twenty20 World Cup trophy, also attended by International Cricket Council (ICC) chief executive Malcolm Speed.
Speed said Twenty20 would be the ideal format if cricket made it to the Olympics. The ICC is seeking International Olympic Committee (IOC) membership.
"That is not saying we are seeking to play in the Olympic Games," he said. "We recognise that is a very long term objective."