Deltoid ligament sprains typically occur when you roll your ankle or when a muscle in the upper ankle is sprained. They are rare, only accounting for 15% of ankle sprains.

Ligaments are vital to your joints working the way they’re supposed to. This WebMD article explains what and where ligaments are and how you can injure them.

The deltoid ligament, a major contributor to medial stability, exhibits a consistent fascicular organisation that, when disrupted, can lead to chronic instability and impaired healing.

"I would say it took me a little longer than expected," Royals said about his recovery. "It was a very delicate injury, a deltoid ligament. But, I'm healthy right now.