From www.soccergaming.com:

Official Word on the Official Patches
We've received word from EA Sports on exactly what the two
patches for FIFA 2000 do. The large one (90mb), as we already
figured out, is for players with American commentary only, as it
changes the game to include the English commentary of Motson
and company.

The other patch, the smaller one (2.5mb) is a multiplayer related
patch. It does the following:

FIFA 2000 Network Patch
README.TXT
December 3, 1999

Installing the Patch
--------------------
1.) Download the patch from the Internet.
2.) Double click on the downloaded executable.
3.) Click "Setup".
4.) Allow the program to finish and close.
5.) Reboot your PC.
6.) The patch is now installed and you may run the game as
normal.

Hard Drive Space Requirements
-----------------------------
During the patch process a total of 6MB of free space is required
on
your hard drive. Once the patch is installed, the patch
executable may
be deleted.

Patch Details
-------------
This patch addresses some of the problems that may be
experienced when
playing network, modem or serial multiplayer games. These
problems occur when connecting different language versions of
the game. After installing the patch these problems will be fixed.

Note: Attempting to connect to a computer which does not have
the patch installed may cause problems, for instance the game
may go out of synch.

Hope this readme helps!