After taking five wickets for 105 runs against New Zealand and ending up with career-best match figures of 9-171 in the second Test here, Lee said he was looking forward to the contest against the South Africans.
"I lost a lot of strength, it only feels now over the last couple of weeks that the strength has come back. The results show that as far as pace and wickets, I have been improving every match," Fox Sports quoted Lee, as saying.
"The next couple of weeks are going to do me a lot of good, I think, being back in the gym and putting back on the kilos that I have lost. I am really proud of taking nine wickets, but I know there is a lot more in the tank," he warned.
Commenting on the South African bowlers, he said: “They have got an amazing bowling line-up and I''m looking forward to watching Dale Steyn bowl. I think he''s got great pace.
"Morkel is six foot six (198cm) and I think he will be pretty challenging at the WACA. It promises to be a nice, bouncy wicket," he added.
Lee''s haul in Adelaide took him to 56 Test wickets at 29.19 runs each in 2008 - second only to Steyn''s 60 at 19.41.
Steyn leads a strong South Africa pace attack that also includes Makhaya Ntini (46 wickets this year) and Morne Morkel (37 scalps at 30.43).
Lee rates Ponting's catch the most amazing!
Australian skipper Ricky Ponting has hailed the coming series as a promoter''s dream and added that Lee"s return to form is a welcome development.
"It is great to see Brett running back into some real rhythm ... his pace was probably higher in this game than it has been for a while," he said.
Australia bowled New Zealand out for 203, completing an innings and 62-run demolition and securing a 2-0 series whitewash.