Volleyball players are extremely susceptible to ankle injuries from all the jumping and landing involved in the sport. You can land incorrectly or land on someone's foot, both of which can result in a sprained ankle.
By strengthening and improving range of motion for your ankle, you can lessen your chance of injury. Ankle injury prevention is about getting the joints loose so you're able to react quickly and move in multiple directions.
Ankle sprains happen when the ligaments in the foot and ankle are stretched beyond their abilities. When ligaments become stretched and too loose, they become unstable--leading to sprains.
Ankle sprains, while common, can be avoided if you train smart. These 6 ankle exercises will help you to maximize strength if you perform then daily.
1. Ankle Alphabet

2. Ankle Rolls

3. Ankle Dorsiflexion

4. Ankle Inversion

5. Single Leg Calf Raises
6. Single Leg Hops

You can find more details about each exercise here: http://www.activekids.com/volleyball/articles/6-stretches-to-prevent-ankle-injuries.