Attacking midfielder Pastore cost Paris St Germain £36m from Palermo two years ago and he would rip a hole in the cash Spurs are demanding for Bale.
Despite insisting their Welsh wizard will not be sold to Real Madrid or Manchester United this summer, it is understood Spurs have already identified who they will try to sign if a deal happens.
Reports in Spain suggest Real are willing to pay a staggering £100m for Bale, which Spurs could find impossible to resist.
Former Tottenham boss David Pleat said: "They were talking £50m, £60m earlier in the summer.
"This could rise to something crazy like £100m.
"At that stage, even Tottenham, who have resisted strongly, may have to look at it. How do you resist that type of money? Manchester United couldn't resist it for Ronaldo."
Pastore can play wide or central, but has not fulfilled his promise at PSG, who are likely to let him go for less than they paid for him.
And Starsport understands that Tottenham’s director of football Franco Baldini has already made enquiries about Pastore’s availability. Meanwhile, Spurs are on the brink of landing Valencia striker Roberto Soldado for £26m. Liverpool were also keen on the 28-year-old, but Spurs are believed to have tied up the deal by agreeing to pay the full buy-out clause.
Baldini had previously seen a £22m offer rejected, but yesterday went back with an improved bid to force the cash-strapped Spanish club to sell.