Do I need a starter?

[spb]

After my last brew I poured the majority of the yeast/trub mixture from my primary into a sanitized plastic container and stored it in the fridge for about a week and a half. I am brewing again tommorow and plan to re-pitch this yeast mixture. Do I need to do a starter or can I just warm up this mixture and throw it in my fresh wort? I have pitched on top of yeast cakes before and had fermentation start in under an hour, isn't just throwing this in the same?
Thanks

 

[Torchiest]

My initial thought is that you wouldn't need a yeast starter, but I've never saved my yeast cakes. I pitched on top of one recently, but that was only about 20mins after I racked the first beer to secondary.