Can I move a site that's out of a Multisite network into it?

Hi

I have a site members.slimtuition.com which I created as a standalone installation with WordPress.

I then, clearly without thinking about it too much, created http://www.slimtuition.com as as WordPress Multisite network with directories.

Is there a way to move the members.slimtuition.com site into the Multisite network? I'd move it to http://www.slimtuition.com/members

Thanks

Gareth