Watson has been struggling recently with a calf injury and is unlikely to be able to bowl, while his fielding practice has been limited to slip catches.
"No one can go into a Test match 70 percent fit. I don't care if you're a batsman and a slip fielder. If you can't bat at 100 percent, then you are putting pressure on other blokes as well," Ponting said.
"It doesn't matter what we think as team-mates, he will have a certain lot of criteria he will have to pass.
"There will be a certain amount of running he will have to do along with other things to prove that he's right to play a Test match.
Australia also has selection doubts over whether to play Mitchell Starc instead of Ben Hilfenhaus.
