He needs to do what Tasha did previous to him and go on a three straight immunity challenge run to avoid getting voted out. He has too many friends on the jury that would vote for him which makes him the immediate danger for everyone else still remaining in the game. If he fails to win a 4-1 vote against him is simply odds on.
2. Kass
With the final 5 consisting of 3 brawns and 2 brains Kass easily slots into this position. Should Spencer claim next weeks immunity the simplest of votes would see Tony/Woo/Trish vote out Kass. It also makes the most sense strategically too as if this were the case come the F4 they will all be desperate to beat Spencer in the immunity challenge and Kass is physically the weakest player still in the game.
3. Woo
Arguably the potential victim of a blindside should one occur next week. Kass has great self awareness in the game even if her strategic moves have been questionable throughout. Should she perceive herself to be at the bottom of the pack if Spencer wins immunity next week her play would have to be to twist the brawn she is closest to, Trish to blindside a brawn, if this were the case they might choose Tony (who is obviously not going home), but if they chose Woo ... the blindside is on if they can attract Spencer. This would make little strategic sense though for the alliance with Woo being the most likely player to topple Spencer in an immunity challenge.
4. Trish
Another but less likely blindside would be Trish. Once more this requires that Spencer wins next weeks immunity challenge. Now we're at the final 5 the thoughts of players are firmly on F3 or F2 (whatever it is) especially Tony's with his idol. What would be the best F3 for Tony? He has a lackey in Woo who he could say to the jury was just following him, there is Kass who has betrayed just about everyone who will be on the jury which leaves ... Trish. It would be a gamble to make the F4 2 brawns and 2 brains with Kass' unpredictability but if Tony is willing to role the dice, in terms of winning the jury over, voting Trish next week is the best possible step for him should Spencer win the immunity challenge.
5. Tony
SCREW THE TP IDOL, I HATE IT WITH A PASSION!!!! Although I won't hate upon Tony, not his fault he has it. #Survivor