I'd be very interested to see who this manager is. Would it be the same one that Ennis had as a player? That would probably be relatively easy to find.
I'm taking a guess here, but could it be the same manager as DCE? DCE is obviously unhappy with Seibold, and is likely part of this segment of the playing group unhappy with Seibold.
I don't believe Mestrov has a player manager. He's a CEO external to the Rugby League affairs in more recent years.
I'd be highly surprised if a Rugby League player agent was working for him, while he was the CEO of Greyhounds NSW, for example.
For me, this is like the wedding rumour. No idea where it came from, but if you use your brain to figure out where Seibold and Mestrov were at different points in the past, it's pretty easy to figure out that both rumours are false.