User Photo and Open Graph

I am using the User Photo plugin (Version 0.9.5.1 | By Weston Ruter) and Open Graph Tools plugin (Version 1.1 | By Joe Crawford). I have inserted the user photo on my single.php posts using userphoto_the_author_thumbnail() within the template file.

The problem is that Open Graph doesn’t pick up that image file when I post an article to a Facebook page. Open Graph doesn’t pick up that image–only any images that I insert into the post.

Can anyone recommend a way to get the user photo to be available to the open graph protocol, or a couple of different plugins that will accomplish this goal?

Thx