Android - Valor Null en GetItemCount - Adapter

return playerList.size();

package com.example.chessplayers;

import androidx.appcompat.app.AppCompatActivity;

import androidx.recyclerview.widget.LinearLayoutManager;

import androidx.recyclerview.widget.RecyclerView;

import android.app.DownloadManager;

import android.os.Bundle;

import android.widget.Toast;

import com.android.volley.Request;

import com.android.volley.RequestQueue;

import com.android.volley.Response;

import com.android.volley.VolleyError;

import com.android.volley.toolbox.JsonObjectRequest;

import com.android.volley.toolbox.JsonRequest;

import com.android.volley.toolbox.StringRequest;

import com.android.volley.toolbox.Volley;

import org.json.JSONArray;

import org.json.JSONException;

import org.json.JSONObject;

import java.util.ArrayList;

import java.util.List;

public class MainActivity extends AppCompatActivity {

    private static final String URL_players = "https://zielsoft.000webhostapp.com/ad_jugadores_ad.php";

    List<Players> playersLista;

    RecyclerView recyclerview;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        recyclerview = (RecyclerView) findViewById(R.id.recyclerView);

        recyclerview.setHasFixedSize(true);

        recyclerview.setLayoutManager(new LinearLayoutManager(this));

        playersLista = new ArrayList<>();

        loadplayers();

    }

    public void loadplayers() {

      //  Toast.makeText(this, "Iniciando", Toast.LENGTH_SHORT).show();

        StringRequest stringRequest = new StringRequest(Request.Method.GET, URL_players, new Response.Listener<String>() {

            @Override

            public void onResponse(String response) {

                Toast.makeText(MainActivity.this, "Respondio", Toast.LENGTH_SHORT).show();

                try {

                    JSONArray array = new JSONArray(response);

                    for (int i = 0; i < array.length(); i++) {

                        JSONObject player = array.getJSONObject(i);

                        playersLista.add(new Players(player.getString("nombre"), player.getString("imagen")));

                    }

                    Adapter adapter = new Adapter(MainActivity.this, playersLista);

                    recyclerview.setAdapter(adapter);

                } catch (JSONException e) {

                    e.printStackTrace();

                    Toast.makeText(MainActivity.this, e.toString(), Toast.LENGTH_LONG).show();

                }

            }

        }, new Response.ErrorListener() {

            @Override

            public void onErrorResponse(VolleyError error) {

            }

        });

        Volley.newRequestQueue(this).add(stringRequest);

    }

}

e com.example.chessplayers;

import android.content.Context;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.ImageView;

import android.widget.TextView;

import androidx.annotation.NonNull;

import androidx.recyclerview.widget.RecyclerView;

import com.bumptech.glide.Glide;

import java.util.List;

public class Adapter extends RecyclerView.Adapter<Adapter.PlayerViewHolder> {

    private Context mCtx;

    private List<Players> playerList;

    public Adapter(Context mCtx, List<Players> playersList){

        this.mCtx = mCtx;

        this.playerList = playerList;

    }

    @Override

    //inicializa la interface de un item y devuelve un viewholder

    public PlayerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        LayoutInflater inflater = LayoutInflater.from(mCtx);

        View view = inflater.inflate(R.layout.lista_layout, null);

        return new PlayerViewHolder(view);

    }

    @Override

    //carga los datos del nuevo item y reutiliza el item para nuevos datos

    public void onBindViewHolder(PlayerViewHolder holder, int position) {

        Players player = playerList.get(position);

        Glide.with(mCtx).load(player.getImagen()).into(holder.imageView);

        holder.txtnombre.setText(player.getNombre());

    }

    @Override

    //cantidad de eementos de la lista

    public int getItemCount() {

        return playerList.size();

    }

    class PlayerViewHolder extends RecyclerView.ViewHolder {

        TextView txtnombre;

        ImageView imageView;

        public PlayerViewHolder(View itemView) {

            super  (itemView);

            txtnombre = itemView.findViewById(R.id.txtnombreJ);

            imageView = itemView.findViewById(R.id.imgJugador);

        }

    }

}