It is not needed really. Yoga does not need karma. Yoga is to go beyond karma. Why karma yoga has been brought in is to bring about balance in a person. Whatever we call as our awareness, our love, our experience or our glimpses of our reality, if it has to be sustained, the path of non-doing is a very wonderful path, but it is very slippery. Extremely slippery. It is the simplest and the most difficult. It is not difficult but it is not at all easy, because it is simple – right now, here and now. But that here and now – how to get it? Whatever you do, it is not in your hands. It is never going to be in your hands. But your hands need something right now, you need to hold something. That is why the crutch of karma yoga.
Without the crutch, most people will not be able to walk. There are a few beings who can walk without the crutch from the first moment. They are very rare beings. Everyone else needs the crutch to manage your awareness. Without this, most people are incapable of remaining aware. So karma yoga is brought into your life to properly temper sadhana with the right kind of action.