i think this it is not possible as you intend to to it. But I would recommend using a Service Container instead of a Repository. In this Service Container you can use different repositories, which you need to use for these global tasks. The Service Container is also accessible in every controller etc..
Here is the Documentatino for it: http://symfony.com/doc/current/book/service_container.html
I don't think that you need the whole injection part. Just define an Service:
services:
linked_service:
class: Acme\LinkedBundleBundle\Service\LinkedService
And then get the service in your controller via
public function indexAction()
{
$service = $this->get('linked_service');
}
Hope this works.