I can't get a seat on the day I want from BKK to SYD.

I am confirmed on BA9 in 3 weeks, and would like to leave a few days earlier. Unfortuantely no award seats available in Z or U on this flight. Currently showing 5F 4A...

If I show up at the airport with a Z ticket for travel 4-5 days later, and there is a seat in F available, will they let me on that day?

cheers


ps. This is on a oneworld award from AA.