I think we should stick with Siddle. Hopefully Clark will be back soon so theres no point chopping and changing the bowlers. I don't think hes ready yet but he is a good prospect. So this is like an investment for the future......oh and remember Johnson took about 10 games to settle in to test cricket.
I am not sure about Krejza but I think hes the best option we got. Atleast hes willing to toss the ball up and try to get wickets . He can also turn and drift the ball , just what you need from an off-spinner. After his debut I think he should give few tests to prove his worth. Just look at Haddin and Johnson , they both had people doubting them after few tests but look at them now. I think its easy to underrate just how hard it is to jump from first class cricket to test cricket.
If theres any change to the side it should be Watson in for Symonds just to give that extra bowling option. Lee , Johnson , Siddle , Watson and Krejza sounds like a pretty good attack. I think Watson is good enough to do that Kallis role with the ball and Kallis did a very important job with the ball in this match. I don't rate his batting , maybe not good enough to bat at 6 but with Haddin and the tail making runs do we really need a specialist at 6 ?