Well, I guess it depends on their credibility. Oh wait, if you are anonymous how can you be credible? You aren't willing to expose yourself to contadiction. It's weak and lazy reporting. It's a fan mag that it came from.
No, it's not lazy. There is some information you're not going to get on the record. I'm a former reporter. I know.
Second, the writer of this piece includes named sources who give an indication of support for the anonymous comments. That's the way it's done. You get enough information from those who WILL go on the record and supplement that will information from anonymous sources.
Third, if it's wrong and egregiously wrong, Aaron Rodgers and Mike McCarthy can sue.
Besides, if not for anonymous sources, President Richard Nixon would have gotten away with felony, we wouldn't have the Pentagon Papers and most of the critical news stories that change society would have remained secrets, and no telling what damage that would have done to our society.