Facebook has announced that from February 20, 2014, page administrators can see who posted on their behalf via the page. The development will enable administrators see the name of an administrator who posted or commented in the name of the page.
According to Facebook,
On a Page post, the name of the person who posted will be listed below the name of your Page next to Posted by. On a Page comment, the name of the person who commented will be listed below the comment next to Commented on by. Keep in mind that only people who help manage your Page can see this information.
The name of an administrator who schedules posts as well will be displayed for other administrators to see.