Yoga is meditation. Meditation is Yoga. Yoga means union - which is BEING one with what you are doing. What we normally consider meditation is actually just one of the eight limbs of Yoga (Dhyana). So yes, give all of yourself to the postures, become the breathing in each asana. Depending on what kind of yoga you are doing and the physical condition you are in, this may take time. So i suggest you make some extra time for some sitting practice. You will see as your sitting becomes more stable, as your mind becomes more focused and calm, this practice becomes YOU. It becomes the way you ARE on a cushion in a yoga class or in worldly life.
I hope this helps.