Implementing a strategy pattern with dependency injection

Okay, so the goal here is to implement a strategy pattern that can be tested using any sort of automated testing tool.

I've been struggling with this problem conceptually for a few weeks now and I want to clarify it.

So the current setup is something like this:

<?php
// CreateReportUseCase.php
class CreateReportUseCase
{
 protected $factory;
 public function __construct(Factory $factory)
 {
    $this->factory = $factory;
  }

  public function create($params)
  {
    // based on something in the params
    // ask the factory to give us one of the strategy classes

    // for this example, let's assume I'm going to execute
    // a different strategy based on the user role.
    // e.g. Admin
    $strategy = $this->factory->make($params['user_role']);

    // execute the strategy using the data out of the params
    $strategy->execute($params);
  }
}

// Factory.php
class Factory
{
  protected $admin_strategy;
  protected $user_strategy;
  public function __construct(AdminStrategy $admin_strategy, UserStrategy $user_strategy)
  {
    $this->admin_strategy = $admin_strategy;
    $this->user_strategy = $user_strategy;
  }

  public function make($role)
  {
    switch($role)
    {
       case 'Admin':
         return $this->admin_strategy;
         break;
       case 'User':
         return $this->user_strategy;
         break;
    }
  }
}

AdminStrategy implements RoleStrategy
{
  public function execute($params)
  {
    // it's not important what we do here.
    return json_encode($params);
  }
}

Does this look sane to you? How could I improve it? To me, the factory looks like it's a bit awkward since it's just returning some injected dependency instead of instantiating a strategy.