How to call just mixed-in methods externally?

Mixin
1

I’m new to Minecraft modding, and I’m learning to modify Minecraft source code with Fabric and Mixin. I just added a sanity level to PlayerEntity (SanityManageris my custom class, and I use Yarn 1.21.4 mapping):

...
@Mixin(PlayerEntity.class) public abstract class PlayerEntityMixin{
    @Unique protected SanityManager sanityManager=new SanityManager();
    @Unique public SanityManager getSanityManager(){
        return sanityManager;
    }
...
}

Then I wanted to display it on HUD, which is managed in InGameHud, I thought. I started mixing-in in another class:

...
@Mixin(InGameHud.class) public abstract class InGameHudMixin{
...
    @Unique private void renderSanity(DrawContext context,PlayerEntity player,int top,int right){
        SanityManager sanityManager=player.getSanityManager();//Cannot compile
    }
}

But when I was trying to get the SanityManager of a PlayerEntity got from arguments, I found that it was the vanilla PlayerEntity syntactically, even though it will be mixed-in my custom method at runtime, so I couldn’t call getSanityManager() directly on PlayerEntity.
I thought transforming it might solve this, but which class should I transform it to ?
I also considered @Shadow, but it can only shadow members in currently mixing-in vanilla class.

Please tell me how to call getSanityManager() from renderSanity(...).