Australia seamer Ryan Harris is confident of being fit for Australia's next Test series, against Pakistan in October, after undergoing knee surgery.

There were fears that Harris' career could be over after he bowled Australia to a last-gasp series win over South Africa in Cape Town last week.

"It's nowhere near my career over," said Harris, who took over as the world's second-ranked bowler after the South Africa series.

"I did this to prolong it more than anything. My knee is damaged - probably a little bit more damaged than the last time they went in a few years ago. But it's still a good knee.

"After what I've put up with in the last few weeks, I can probably put up with just about anything now.

"I'm already looking forward to hopefully getting back for the Pakistan tour. That's my goal, and a very realistic goal."

The injury-prone 34-year-old had long been due to go under the surgeon's knife, after piecing together 12 consecutive Tests - easily the longest run of his late-blossoming career.

Harris visibly struggled with the problem during the South Africa series while it locked on him during the flight home.

Tuesday's knee surgery therefore came as "good relief" even though Harris expects to one day need a complete replacement.

With that in mind he has told his surgeon to try and extend his career for another couple of years - which would at least take him through to next summer's Ashes series in England.

"I've already told the surgeon just keep me on the park for another two or three years and we'll worry about that (the knee replacement) later," Harris said.

"I'll give him his money later, it's already guaranteed.

"I probably am (going to need a replacement) at some stage. But again I just want to do whatever I can now to keep playing in this team and enjoying the success that we've been working so hard to get to."

For now Harris, who fronted the media in Melbourne on crutches, is just happy to have rid himself of knee pain, which flared midway through the 5-0 Ashes whitewash.

"It's feeling better today and yesterday than it felt before I went in," he said.

"It's good relief. A couple of days after the last win and when I got home it was actually quite painful. It's been cleaned out, which is what I've been waiting for for a while.

"There was a fair bit in there. I saw a couple of pictures of quite big pieces of cartilage. They were a lot bigger than what I thought they were going to be."