Sidelined Australian opener Simon Katich says his Achilles injury is recovering quicker than expected, putting him on track for a possible surprise comeback in the final Ashes Test.

Katich, 35, said he was "really happy" at how the partial tear was reacting to rehabilitation and physiotherapy after he hobbled through the second Test in Adelaide and was ruled out for the rest of the series.

"I'm doing all the rehab and pulling up well from the strength work so the physio's pretty happy with where I'm at and actually thinks I'm ahead of schedule," Katich said.

"Normally it takes a couple of months to settle down but it's settling down pretty quickly.

"I've been having treatment on it every day for the last few weeks and it's all going really well."

Asked if he would be fit in time for the final Test in Sydney, Katich replied: "I'm a long shot but you never know.

"You can't really put a date on it because with tendon injuries you never know until you fully test them, but if I test it next week and pull up well then who knows.

"I am doing everything I can to get it right so we'll wait and see.

"I will keep upping the ante with the strength work and we might consider testing it with a run next week to see how it pulls up.

"But I haven't discussed it (a return) with the selectors and that would be for them to decide, not me."

Katich was replaced by New South Wales' Phillip Hughes, who scored only two and 12 in last week's Perth Test.

"It's a tough job over there in Perth. The wicket had some life with the new ball and it was tough for the openers," added Katich.

"I'm sure Phil will be fine in Melbourne's fourth Test."