Doctrine 2 + ZF2: Create entities via ServiceManager

Question

In a Zend Framework 2 app, I have some Doctrine2 entities that have dependencies, which are injected into them by the ServiceManager, i. e. an Order needs a new Invoice whenever it is created.

'service_manager' => [
    'invokables' => [
        'Sales\Entity\Invoice' => 'Sales\Entity\Invoice'
    ],
    'factories' => [
        'Sales\Entity\Order' => function($sm) {
            $order = new \Sales\Entity\Order();
            $order->setInvoice($sm->get('Sales\Entity\Invoice'));
            return $order;
        }
    ],
    'shared' => [
        'Sales\Entity\Invoice' => false,
        'Sales\Entity\Order' => false
    ]
]

With this configuration, it is no problem to create a new Order that has a new Invoice assigned to it anywhere in the application, because for example inside a controller I can just call

$order = $this->getServiceLocator()->get('serviceManager')->get('Sales\Entity\Order');

However, when retrieving an Order via an EntityRepository, the dependencies won't be injected because as far as I know, Doctrine instantiates an entity by calling its constructor and then cloning this instance whenever it needs another one. Doctrine thereby bypasses the ServiceManager and hence the dependency injection.

I. e.

$order = $entityManager->getRepository('Sales\Entity\Order')->find(42);

will give me an order without a new Invoice.

I know directly injecting dependencies into entities might not be the best solution, but at this moment we are working with fat models in our application without a model service layer and for a quick fix, I have to get this to work. Refactorings are planned for the future but are not up for discussion right now.

Is it possible to change the way Doctrine instantiates a new entity? I dipped into the EntityManager and EntityRepository, but have not yet found a solution.