Injecting Mockito mocks into beans returned through factory methods

I have the following set up:

A sample class that needs to be mocked during testing:

@Component
class MyConfig
{
    public String getConfig()
    {
        return "RealValue";
    }
}

An interface that defines a single method and has two implementations:

interface MyInterface
{
    String myMethod();
}

class MyImpl1 implements MyInterface
{
    private final MyInterface delegate;
    private final MyConfig config;

    public MyImpl1(final MyInterface delegate, final MyConfig config)
    {
        this.delegate = delegate;
        this.config = config;
    }

    @Override
    public String myMethod()
    {
        return this.getClass().getSimpleName() + ": " + config.getConfig() + ", " + delegate.myMethod() + ";";
    }
}

class MyImpl2 implements MyInterface
{
    private final MyConfig config;

    public MyImpl2(final MyConfig config)
    {
        this.config = config;
    }

    @Override
    public String myMethod()
    {
        return this.getClass().getSimpleName() + ": " + config.getConfig();
    }
}

A factory class that prepares a bean of type MyInterface using the MyConfig object that is a spring bean injected into MyFactory:

@Component
class MyFactory
{
    @Autowired
    private MyConfig config;

    // Factory method to create the bean.
    @Bean(name = "myInterface")
    protected MyInterface myInterface()
    {
        final MyImpl2 myImpl2 = new MyImpl2(config);
        final MyImpl1 myImpl1 = new MyImpl1(myImpl2, config);
        return myImpl1;
    }

    // A simple getter that prepares MyInterface on the fly.
    public MyInterface getInterface()
    {
        final MyImpl2 myImpl2 = new MyImpl2(config);
        final MyImpl1 myImpl1 = new MyImpl1(myImpl2, config);
        return myImpl1;
    }
}

A simple test case that checks if the mock version of MyConfig is getting into the bean created using @Bean or not:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {
    "classpath:application-context.xml"
})
public class SpringBeanMockExampleTest
{
    @Mock
    private MyConfig config;

    @InjectMocks
    @Autowired
    protected MyFactory factory;

    @Resource
    private MyInterface myInterface;

    @Before
    public void setupMocks()
    {
        MockitoAnnotations.initMocks(this);
    }

    @Test
    public void testBean()
    {
        Mockito.when(config.getConfig()).thenReturn("MockValue");
        /**
         * Fails as the return value is "MyImpl1: RealValue, MyImpl2: RealValue;"
         */
        Assert.assertEquals("MyImpl1: MockValue, MyImpl2: MockValue;", myInterface.myMethod());
    }

    @Test
    public void testGetter()
    {
        Mockito.when(config.getConfig()).thenReturn("MockValue");
        Assert.assertEquals("MyImpl1: MockValue, MyImpl2: MockValue;", factory.getInterface().myMethod());
    }
}

I expected the testBean method to pass also, but obviously the mock is not getting injected into the factory bean created in MyFactory. How can I fix this so that testBean works as expected?