Overloading << operator in template linked list with inheritance

I'm trying to overload << operator within a template linked list.

in short I have one abstract class and 2 derived classes that inhered him. all 3 classes have operator << written & working well if I use dynamic_cast.

But when I try to use operator << within the template linked list I either get the address or a linker error for some reason.

Abstract class - Player

#ifndef PLAYER_H_
#define PLAYER_H_
#include <iostream>

class Player {
private:
  const char* m_name;
  int age;
public:
  static int numofPlayers;
  Player(const char*,int);
  virtual ~Player();
  friend std::ostream& operator<<(std::ostream& out, const Player &p);
};

std::ostream& operator<<(std::ostream& out, const Player &p);

#endif

One of the derived classes

class Goalkeeper:public Player {
private:
  int Saved_Goals;
  int Shirt_Number;
public:
  Goalkeeper(const char* name,int age, int number);
  ~Goalkeeper();

  friend std::ostream& operator<<(std::ostream& out, const Goalkeeper& s);
};

std::ostream& operator<<(std::ostream& out, const Goalkeeper& s);

Both of the << operators for base & derived work well! Only when I try to use them in the template linked list I get the address and not the data:

Template Linked List

template <typename T>
class Node {
  T* m_data;
  Node* next;
public:
  Node ();
  Node(T*, Node<T>*);
  ~Node();
  T* getData ()const {return this->m_data;};
  Node* getNext()const{return this->next;};
  template <typename T>
  friend std::ostream& operator<<(std::ostream &output, const Node<T>& Nd );
};

template <typename T>
std::ostream &operator << (std::ostream &output,const Node<T>& Nd ) {
  output<<Nd.m_data<<endl;
  return output;
}

template <typename T>
void List<T>::PrintMe() const {
  Node<T>* temp=this->head;
  while(temp) {
    cout<<*temp;
    temp=temp->getNext();
  }
}