After the Philadelphia draw has been made, there is only one scenario left in which Patty drops to No.9:
1. Patty must lose her SF tomorrow.
2. Petrova must win Linz.
3. Both Petrova and Dementieva must advance to the Philadelphia semifinals, with Dementieva winning their match and also the tournament.
IMO, this is rather unlikely.
So by winning tomorrow, Patty is qualified. If she doesn't win, no big deal.
Note: I assume that no WC is given to someone who's not fit and/or not motivated to qualify directly.
She'll go 1-2 in round robin play and be one of the first to be eliminated.
who is going to beat her?
Maria is hardly looking great. Momo is looking decidedly bad, Juju looks like being absent as does Venus. Mary may be ok or injured and 5 matches against top players takes her past the point she has been losing finals. Nadia looks tired. That just leaves Elena D who is competitive and Kim and Lindsay who can outplay her but who she can probably beat on the right day.