As much as we'd like to know we have no automatic right to that information.
If the player says he doesn't want the world to know then the club can't do anything about that without risking fines under the Data Protection Act.
Health is classified as Special Category data by the Information Commissioners Office so if the player says 'no' that's it. There is no necessary reason to process the data (send it out to the fans) that will over-ride.
I know as fans it's frustrating but the players have a right to privacy and not everyone wants to live their life on Instagram 'Smashing a Nando's' or giving a thumbs up in a hospital recovery room?