The defence plans to call former central bank governor Azeema Adam.
The incumbent should admit failure and resign, the opposition leader said.
The opposition leader was hospitalised three times since his detention.
The opposition leader was detained for the duration of a money laundering trial.
The PPM congress in September where Yameen was elected president was legitimate, the Supreme Court ruled.
Yameen is accused of money laundering and giving false information to the anti-corruption watchdog.