public class Team
    {        
        public Team() 
        { 
            Players = new List<Player>(); 
        }
        public long ID { get; set; }
        public string Name { get; set; }
        public List<Player> Players { get; set; }
    }

    public class Player 
    {
        public long ID { get; set; }
        public string Name { get; set; } 
        public string Position { get; set; }
        public long Team_ID { get; set; }
        //public Team Team {get;set;} //вот это мне вообще здесь не нужно!
    }

public class TeamConfiguration : EntityTypeConfiguration<Team>
    {
        public TeamConfiguration()
        {            
            HasKey(c => c.ID);
            Property(c => c.Name).HasMaxLength(50).IsRequired();
            //HasMany(c => c.Players)
            //    .WithRequired(p => p.Team)
            //    .HasForeignKey(p => p.Team_ID);
            ToTable("Teams");
        }        
    }

    public class PlayerConfiguration : EntityTypeConfiguration<Player> 
    { 
        public PlayerConfiguration() 
        {
            HasKey(c => c.ID);
            Property(c => c.Name).HasMaxLength(50).IsRequired(); 
            Property(c => c.Position).HasMaxLength(50).IsRequired();
            Property(c => c.Team_ID).IsRequired();
            //HasRequired(x => x.Team)
            //    .WithMany(o => o.Players)
            //    .HasForeignKey(ol => ol.Team_ID);
            ToTable("Players");
        } 
    }

public class MyDbContext : DbContext
    {
        public DbSet<Team> Teams { get; set; }
        public DbSet<Player> Players { get; set; }
        
        public MyDbContext() :
            base("DBConnectionString")
        {
            this.Configuration.LazyLoadingEnabled = true;
            this.Configuration.ProxyCreationEnabled = false;
        }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {            
            base.OnModelCreating(modelBuilder);

            modelBuilder.Conventions.Remove<IncludeMetadataConvention>();
            modelBuilder.Configurations.Add<Team>(new TeamConfiguration());
            modelBuilder.Configurations.Add<Player>(new PlayerConfiguration());            
        }         
    }

var hc = new MyDbContext();
            Team team = hc.Set<Team>().SingleOrDefault(x => x.ID == 22);

HasMany(x => x.Players).Table("Players").KeyColumn("Team_ID").Cascade.All(); 

Team team = hc.Teams.Include(x => x.Players).Where(c => c.ID == 1).Single<Team>();

SELECT 
[Project2].[C1] AS [C1], 
[Project2].[ID] AS [ID], 
[Project2].[Name] AS [Name], 
[Project2].[C2] AS [C2], 
[Project2].[ID1] AS [ID1], 
[Project2].[Name1] AS [Name1], 
[Project2].[Position] AS [Position], 
[Project2].[Team_ID] AS [Team_ID]
FROM ( SELECT 
	[Limit1].[ID] AS [ID], 
	[Limit1].[Name] AS [Name], 
	[Limit1].[C1] AS [C1], 
	[Extent2].[ID] AS [ID1], 
	[Extent2].[Name] AS [Name1], 
	[Extent2].[Position] AS [Position], 
	[Extent2].[Team_ID] AS [Team_ID], 
	CASE WHEN ([Extent2].[ID] IS NULL) THEN CAST(NULL AS int) ELSE 1 END AS [C2]
	FROM   (SELECT TOP (2) 
		[Extent1].[ID] AS [ID], 
		[Extent1].[Name] AS [Name], 
		1 AS [C1]
		FROM [dbo].[Teams] AS [Extent1]
		WHERE 1 = [Extent1].[ID] ) AS [Limit1]
	LEFT OUTER JOIN [dbo].[Players] AS [Extent2] ON [Limit1].[ID] = [Extent2].[Team_ID]
)  AS [Project2]
ORDER BY [Project2].[ID] ASC, [Project2].[C2] ASC

Team team = hc.Teams.Include(x => x.Players).Where(c => c.ID == 1).Single<Team>();