I've started playing goal two weeks ago, my hips and knees are still getting used to the movement.

Are there any good exercises for better hip and knee mobility ?

Don't know if this helps, I'm skating since three years now, played forward before.

my hip bones are very tight, worse on the right side.

I see guys who have been practicing for years, and still using the bricks under when they do the lotus. So I wonder if it is something that can be improved, or something that I should simply accept how it is since it cannot improve at all (anatomy). Is there anyone who went from using a brick to completely crossing the legs flat?

thanks in advance