Royce O’Neale
If Miami were to trade Caleb Martin, then Royce O’Neale would be a suitable replacement. O’Neale is your prototypical 3-and-D wing and, in today's NBA, you need guys with O’Neale’s skillset.
Like Martin, O’Neale can play multiple positions. He is a solid shooter, a solid defender, and a sneaky-good playmaker. O’Neale would be an upgrade over Martin defensively. Having another wing defender is something Miami should consider.
O'Neale knows what it takes to be on a good team defensively. When O'Neale played for the Utah Jazz, they were always a top-10 team defensively. That shows he understands defensive principles and knows where to be.