Depends on the age of the LO, but they can often balance out over the day if you're careful with the next one. It's good not to be too 'afraid' of the cr@p nap, it can stop you doing things you need to do
but it's also good to bear the LOs needs in mind and try to find a middle way. Of course there are days when they just do not nap well, and there's nothing you can do. When that happens, you need chocolate
and a sense of perspective - one nap, one day, a week or so, none of it is the end of the world. Good enough is good enough