@bainhardt
In women's tennis, you'll find both and then some. I would say that a true skort is rare however, and I've never seen one worn, at least not at the WTA pro level. I say that because a proper skort is actually shorts, but with a skirt panel on the front. In general, tennis skirts and skorts are designed the same; it's a skirt with shorts built in to allow them to carry their second service ball in a pocket under the skirt.
That said, you can wear separate bloomers like Minamine-san is doing here. But again, it's not something I've seen at the pro level, so it might be more common in juniors.