Pot Cooker Do You Need To Seal Beef Before Putting It Into A Crock Pot/slow Cooker?

Do you need to seal beef before putting it into a crock pot/slow cooker? - pot cooker

I always seal the meat in a pan before it in the crock pot (slow cooker) with sauce, etc., but now I have quite forgotten, and put it directly into the pot, and now more than 3 hours later. Not always want to eat or cook / taste right?
Thx