Validating users with Roles
public Users VerifyPassword(string userName, string password)
{
    //The ".FirstOrDefault()" method will return either the first matched
    //result or null
    Users myUser = SoccerEntities.Users
        .FirstOrDefault(u =&gt; u.UserName == userName
                     &amp;&amp; u.password == password);



    if (myUser == null)    //User was not found
    {
        //Proceed with your login process...
        return myUser;
    }
    else    //User was  found
    {
        if (isPlayerdb(userName))
            isPlayer = true;
        if (isAdmindb(userName))
            isAdmin = true;

        return myUser;        
        //Do something to let them know that their credentials were not valid
    }
}  



The comments in this method don't serve any purpose an don't add any value to the code, so get rid of them. Comments should describe why something is done but shouldn't state the obvious.  

A class named Users implies to hold a collections of User but in your case it seems to be singular so you should rename this class to User.  

Not using braces {} will lead to error prone code. You should use them always although they might be optional.  

The else part is redundant because if myUser == null it won't be reached, you should get rid of the else.  

If for instance isAdmin had been true before this call it will stay that way which is bad. Just assign the returned value of isAdmindb to the variable. The same goes for isPlayer.  

Applying this points except for Users vs User 

public Users VerifyPassword(string userName, string password)
{

    Users user = SoccerEntities.Users
        .FirstOrDefault(u =&gt; u.UserName == userName
                     &amp;&amp; u.password == password);

    if (user == null) { return null; }

    isPlayer = isPlayerdb(userName);

    isAdmin = isAdmindb(userName);

    return user;        

}  


looks much cleaner, doesn't it ? But hold on, we can do better.  

If we take a look at isAdmindb() we notice at first, that the method name doesn't match the NET naming guidelines regarding the used case of the name. Method names should be named using PascalCase casing.  

The next thing is that a user is considered an admin if its roleId matches a specific Guid. So let us take this Guid and use it in the VerifyPassword() method. But wait, this doesn't seem right because the responsibility of that method should be only to verify that the used username and password are correct. So there shouldn't be anything related like in the former method with the isAdmin stuff.  

So let us change the isAdmindb() method to take a Users opject as a method argument and compare the user's roleId with the said Guid which we extract to a class member constant.  

private const Guid adminRoleId = new Guid("ED85788D-72DA-4D0A-8D5E-B5378FC00592");
protected bool IsAdmin(Users user)
{
    return user.roleId == adminRoleId ;
}  


now thats short and readable and doesn't need to hit the db.  

Now we should take the VerifyPassword() and change it to GetUser() and remove all this stuff about the isAdmin and isPlayer leaving only this  

public Users GetUser(string userName, string password)
{

    return SoccerEntities.Users
        .FirstOrDefault(u =&gt; u.UserName == userName
                     &amp;&amp; u.password == password);
}  


Now let us add a FormsAuthenticationTicket GetAuthenticationTicket(Users)  method which will do some of the work which had formerly been done by the eventhandler of that button.  

private FormsAuthenticationTicket GetAuthenticationTicket(Users user)
{
    return new FormsAuthenticationTicket(
          version: 1,                                     
          name: user.UserName,                           
          issueDate: DateTime.Now,                        
          expiration: DateTime.Now.AddMinutes(30),        
          isPersistent: isPersistent,                     
          userData: user.ToString(),                             
          cookiePath: FormsAuthentication.FormsCookiePath);
}  


as you see by using named arguments there is no need for any comment anymore. 

Now the former eventhandler code will look like  

protected void btnLogin_Click1(object sender, EventArgs e)
{
    Users user = GetUser(txtUserName.Text, txtPassword.Text);

    if (user == null)
    {
        lblerror.Text = "Invalid Login";
        return;
    }

    FormsAuthenticationTicket ticket = GetAuthenticationTicket(user);

    isAdmin = IsAdmin(user);
    isPlayer = IsPlayer(user); // should be implemented by you in a similiar way

    string encryptedTicket = FormsAuthentication.Encrypt(ticket);

    HttpCookie cookie = new HttpCookie(FormsAuthentication.FormsCookieName, encryptedTicket);
    cookie.HttpOnly = true;
    Response.Cookies.Add(cookie);

    lblerror.Text = "Success!";

    Response.Redirect("default.aspx");


}