Katich, who was called on as a replacement to injured batsman Matthew Hayden, could well face the axe if the opener recovers from his Achilles injury and resumes his place.
''I was just grateful to be on the tour as an extra batsman, and the opportunity to play has been great because I felt that I was ready to play well given my form in the last couple of years,'' Katich was quoted as saying in Sydney Morning Herald.
''Obviously, I know that when Matt is back in the team, he and Jaquesy have done a great job, so I'll just have to bide my time, but it's nice to be playing well rather than struggling and possibly being on the outer,'' he added.
For the second time in as many Test matches, Katich displayed great determination and skill to bat for an entire day and guide the Australians to a formidable total.
His unbeaten 148 on Saturday was his best Test score, and formed part of a 223-run stand with Phil Jaques - the second-highest second innings opening partnership by an Australian pair - to help propel the tourists to three for 330 at stumps, an overall lead of 365 runs.
The other Australian opener Phyll Jaques, however, admitted that he and Katich are competing for the same spot with Hayden set to make his return in to the side.
''Definitely, especially when you've got a guy like Simon breathing down your neck,'' Jaques said. ''He's knocking the door down and playing some really good cricket.
''We all know Matthew Hayden is coming back into the team at some point. We've both been trying to make every post a winner and make as many runs as possible,'' Jaques added.