Subdomain blog page on standalone WP install

OK, so i have a client with a standard wordpress site who wants to have his blog page @ To be clear I am not talking about a redirect where a user puts in and gets redirected to In all my experience with wordpress the only way that i know how to achieve this is through wordpress multisite. However I do not declare myself an expert so I figured I would as to see if anyone has a solution to this with out changing over to WP Multisite

Thanks in advance for the Help!