FK_Field1 | FK_Field2
NULL         1
10             NULL 

Table1
T1_Id    T1_Name
1        Zenit
2        Spartak

Table2
T2_Id   T2_Name
10      AK BARS
20      Dinamo

Table3
T2_Id    Type      FK_ID
1        Football  1
2        Hockey    1

CREATE TABLE [dbo].[Table3](
	[Id] [int] IDENTITY(1,1) NOT NULL,
	[Type] [varchar](255) NOT NULL,
	[FK_ID] [int] NOT NULL,
 CONSTRAINT [PK_Table3] PRIMARY KEY CLUSTERED 
(
	[Id] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

GO

SET ANSI_PADDING OFF
GO

ALTER TABLE [dbo].[Table3]  WITH CHECK ADD  CONSTRAINT [FK_Table3_Table1] FOREIGN KEY([FK_ID])
REFERENCES [dbo].[Table1] ([T1_Id])
GO

ALTER TABLE [dbo].[Table3] CHECK CONSTRAINT [FK_Table3_Table1]
GO

ALTER TABLE [dbo].[Table3]  WITH CHECK ADD  CONSTRAINT [FK_Table3_Table2] FOREIGN KEY([FK_ID])
REFERENCES [dbo].[Table2] ([T2_Id])
GO

ALTER TABLE [dbo].[Table3] CHECK CONSTRAINT [FK_Table3_Table2]
GO

Table3
T2_Id    Type      FK_ID
1        Football  1
2        Hockey    10

Sport {Sport_Id, Sport_Type, < attr... >}; 
Soccer {Sport_Id, Sport_Type, < attr ... >}; constraint: {Sport_Type = 'Soccer'};
Hokey {Sport_Id, Sport_Type, < attr ... >}; constraint: {Sport_Type = 'Hokey'};

ForeinKey: Sport (Sport_Id, Sport_Type) reference Soccer (Sport_Id, Sport_Type);
ForeinKey: Hokey (Sport_Id, Sport_Type) reference Soccer (Sport_Id, Sport_Type);

Sport
Sport_Id Sport_Type
--------------------------------
1           Soccer           ...
22          Hokey            ...
2           Soccer           ...
1           Hokey            ...

Hokey
Sport_Id Sport_Type
-------------------------------
1           Hokey            ...
22          Hokey            ...

Soccer
Sport_Id Sport_Type
--------------------------------
1           Soccer           ...
2           Soccer           ...