Невозможно использовать сравнимое с наследованием отец-сын-внук

Дан следующий код:

public abstract class Participant {
    private String fullName;

    public Participant(String newFullName) {
        this.fullName = new String(newFullName);
    }

    // some more code 
}


public class Player extends Participant implements Comparable <Player> {    
    private int scoredGoals;

    public Player(String newFullName, int scored) {
        super(newFullName);
        this.scoredGoals = scored;
    }

    public int compareTo (Player otherPlayer) {
        Integer _scoredGoals = new Integer(this.scoredGoals);
        return _scoredGoals.compareTo(otherPlayer.getPlayerGoals());
    }

    // more irrelevant code 
}

public class Goalkeeper extends Player implements Comparable <Goalkeeper> { 
    private int missedGoals;        

    public Goalkeeper(String newFullName) {
        super(newFullName,0);
        missedGoals = 0;
    }

    public int compareTo (Goalkeeper otherGoalkeeper) {
        Integer _missedGoals = new Integer(this.missedGoals);
        return _missedGoals.compareTo(otherGoalkeeper.getMissedGoals());
    }

    // more code 
}

Проблема в том, что Вратарь не подчиняется.

Когда я пытаюсь скомпилировать этот код, Eclipse выдает:

The interface Comparable cannot be implemented more than once with 
different arguments: Comparable<Player> and Comparable<Goalkeeper>

Я пытаюсь сравнивать не с Player , а с Goalkeeper , и только с ним.

Что я делаю не так?