Palace have rejected an increased £2million bid for Routledge from Spurs because it falls short of their £4m valuation.
Chairman Simon Jordan said: "Spurs approached me after the game but they have not offered us anywhere near enough for a player we want to keep."
Despite the uncertainty, manager Iain Dowie did not consider dropping the England Under-21 international for the London derby. He was rewarded for his decision when Routledge set up Danny Granville for Palace's second goal.
The defender's strike followed Leigertwood's second-half opener and gave Palace a decisive advantage. Andy Johnson sealed the points with a 71st-minute penalty.
Leigertwood said: "It was our best performance of the season and to score my first Premiership goal was special.
"We have shown now we can compete against the better teams and that should put us in a good position going forward.
"We have got the passion and desire to stay up and although we have not got a massive squad, we've also got people who are good enough to come in and do a job."
For Martin Jol, Spurs' second-half display highlighted the need to sign a new striker before the end of the month.
With Fredi Kanoute injured, Robbie Keane and Jermain Defoe are his only senior forwards.
The Dutch head coach said: "I always said we need four strikers. Now, if you have one injury - like with Kanoute - then we only have two.
"Robbie and Jermain are terrific players but it's all about the combination. When we don't build up well from the back, as happened against Palace, then we have a problem. We hit long balls and it looks a bit awkward."
Spurs winger Reto Ziegler limped off with a hamstring injury and could be sidelined for up to six weeks.
