Is my tranny going?

[streetknight]

I noticed that over the last few times I've drove my car the shift has gotten a little soft. I raced it Sunday and now when just cruising when the car shifts into Drive as long as the RPM's are below 2300 the rpm's jump up about 300rpm's before it goes in gear. At higher rpm's it seems fine, just not as firm.

Is this a warning sign?

Thanks in advance