Google index follow backend

Hi,
I noticed that my site have command for Google and other bots INDEX, FOLLOW.
My robots.txt file have line:

Disallow: /admin

As I can see most of backend URLs are:

https://site.com/Admin/Setting/GeneralCommon
https://site.com/Admin/Product/List

...
So, my question is, should I add following command into robots.txt file?

Disallow: /admin/*

I am just worry not to block Google bot where I shouldn't.
Thanks a lot for looking into.

It actually doesn't matter, both Disallow: /admin and Disallow: /admin/* will give you almost the same result. But the first one will disallow the page www.site.com/admin and the second one won't, that's the only difference. So if you need Google bot to see the given page, choose Disallow: /admin/*, and if you don't need Google bot to see this page, choose Disallow: /admin