He suffered a hamstring injury during the latter part of the fifth test but has recovered sufficiently to make his first class comeback.
Harris was left out of the squad currently touring India for a one-day series to give him time to recover and rejoin Australia for the Ashes and while he is determined to stay fit he knows his body could have other ideas.
"I could snap ... who knows. I'm probably going to have another major injury before I finish," said Harris. "I just hope it's not in the next six months."
The right-arm paceman's international career has been blighted by a chronic knee problem, left ankle fracture, shoulder problem, back strain, hip pain and a tender Achilles.
With only 16 tests to his name, he is excited at the prospect of spearheading Australia's pace attack once again in the first Ashes test beginning in Brisbane on November 21.
"I have laid in bed a few nights and tried not to think about it ... but if I have got the new ball at the Gabba in the first over, it's going to be pretty exciting.
"If we play well, I think we'll beat them, as simple as that. We have just got to make sure we play consistently."
Fellow quick Mitchell Johnson's form in India also gave Harris cause to be optimistic.
"It's so good to see him bowling fast and with swing and scaring the Indians," Harris said. "He copped a lot of stick a few years ago, especially over in England.
"And it would be great to bowl in a partnership with him ... and at the end of the series, sit there with a little Ashes urn next to us."
(Reporting by Amlan Chakraborty in New Delhi, editing by Peter Rutherford)
