How to Initialize class without instantiating a Game Object?

I am working on a Project in Unity where the Player on the Client side needs to connect to the Server running on another Unity Console Build. Anyways, on the Server side, there is a Client Class that handles all the Connections and Data Handling through a TCP Class but, there is also a Player Class, that needs to hold all the necessary information about the Player, like Display Width, Health Points and so on… Here is a sample of the Client Class:

public class Client
    public Player player;
    public TCP tcp;

    public Client(int _clientId)
        tcp = new TCP(id);
        player = new Player();

    public class TCP
        //all the necessary variables for the workings of TCP
        public TCP(int _id)
            id = _id;

Here is a sample of the Player Class:

public class Player
    public int id;
    public string username;

    public void Initialize(int _id, string _username)
        id = _id;
        username = _username;

I didn’t include all the code since it’s unnecessary for this topic.

My question is, how can I instantiate a Player class for every player that connects. How can I get the reference for every player and store it in an Array? I DON’T need to instantiate a Capsule or any Game Object, just the plain class to hold the information for each Player. I would need to be able to do something like this:

Client[] clients = new Client[20];
//calling the constructor in a for loop

clients*.Initialize(i, _username);*

That’s all. If for some reason the information I provided is not clear, I would happily add more details if needed. Thank you for your time.

I think you could achieve what you are looking for with a list.

  List<Player> playerList;    

Then in your server’s start function

playerList=new List<Player>();

Then when a player connects:

playerList.add(new Player);

And when you want to call a function for a given player;

playerList[int playerID].myFunction(params);

And when a player quits;

playerList.RemoveAt(int playerID);