If you are an athlete suffering from achilles pain, start with trying these 3 things:
Calf stretch- hold for long duration with a low load. A less intense stretch held for a longer period of time will help to improve the length of the calf and achilles tendon and reduce stress during activity.
Eccentric calf raises- this is a calf raise with an emphasis on slowed lowering. If your right is the affected side, you could go up with 2 and down with 1 using only your right to increase the load during the eccentric phase.
Dynamic calf mobilization- Do this in a lunge position. Move forward and backward pressing the ankle into dorsiflexion.
Let us know if this helps!