Clarke rolled his right ankle during fielding training on Monday at Adelaide Oval and did not train the next day.
On Wednesday, the Australian skipper watched his teammates perform fielding drills and then batted in the nets for about 40 minutes, appearing untroubled by the injury.
Clarke declared himself a certain starter as the Australians seek to build on their 1-0 series lead.
"The ankle feels fine," Clarke told reporters after training.
"I think not training yesterday obviously gave me an extra day to make sure I was 100 per cent today, I feel completely fine."
Australian selectors were pondering changing their first Test team, which crushed England by 381 runs in Brisbane in the series-opener, by replacing middle-order batsman George Bailey with allrounder James Faulkner.
But Clarke said selectors opted to stick with the same 11 players who won the first Test, with Faulkner again to be 12th man.
"It's a real positive to where the team is at, and how we performed in Brisbane," Clarke said of retaining the same team.
"I can't say I spoke too much to the selectors about it (changing the team). They obviously looked at the wicket and thought about the extra bowling option with James Faulkner in the team.
"But obviously having Watto (Shane Watson) who can bowl and is back to 100 per cent, being fit and capable of bowling in both innings, is a real positive for the team.
"I think Watto's overs, through his career, we have seen are crucial to this team and on good flat wickets like this wicket looks out here, I think his bowling is going to be very handy for not just taking wickets but also for building pressure from one end."
Clarke also said Australia wouldn't change its aggressive approach from the first Test, which was marred by verbal clashes with the tourists.
"We will continue to play a tough brand of cricket on the field ... we all know there is a line we can't cross," he said.
"We still have the ultimate respect for our opposition."