Way to Disable Game without removing current players.???

Is there a way to disable a game from being accessed by the players without deleting them from the game?

There is not.  

Just create a blank page, stick them there, and use /talktomyself to test macros and such without players being able to see them and glean some knowledge of what they might be facing in the future.

SkyCaptainXIII said:

Just create a blank page, stick them there, and use /talktomyself to test macros and such without players being able to see them and glean some knowledge of what they might be facing in the future.

What SkyCaptainXIII said is a good method. Park the Players Ribbon on a 'splash page' and use /talktomyself to hide whatever you might do in the chatroom side.

Wiki docs for this,
https://wiki.roll20.net/Text_Chat#Talk_to_Myself_....

Another technique for Pro subscribers, you can do certain work in a different game (your holding-tank or set-up game) and then use Transmogrifier to move your work over into your main game that has the players. This technique works for any of the elements that Transmogrify can move.

Wiki docs,
https://wiki.roll20.net/Transmogrifier