Are you talking no post-doc at the VA, no formal post-doc, or no post-doc at all? I know a few people, including myself, that took a job instead of a formal post-doc and were supervised who now work at a VA as well as several that did post-docs in other places. There are some states that will license you straight out of grad school, but that is fairly new so I am not sure how hiring committees are looking at that. However, post-docs are becoming more standard for many VA positions, especially in the more competitive ones. My feeling is that if you don't do one, you will need a few years of experience as a licensed clinician to get hired.