I've just bought some fresh rump steak to make beauf bourguignon in 3 days. Can I keep it in a fridge or do I need to put it in a freezer? 
A roast should be fine for 3-4 days, refrigerated see:  Beef board reference  If any of several modern packaging systems are used--most of which are designed to exclude air and pathogens, you can get significantly longer storage, although freezing is probably still not a bad idea:  Beefresearch.org 