Ross Greenburg is definitely out as President of HBO Sports, but there's spin on the issue avoiding the idea that he was fired or forced out, and instead making it seem as though it was a choice to step down. Richard Sandomir has the following from his Twitter:

Ross Greenburg to me: "It was getting to the point where I wasn't enjoying myself. Boxing taking up too much of my time."

Greenburg, on boxing: "It was hard to satisfy everyone." Says departure nothing to do with Pacquiao fighting on Showtime

Greenburg said he loves boxing, loved producing it, "but majority of my time was spent appeasing promoters and managers."

HBO and Greenburg (as well as Kery Davis, who is also reportedly on the outs) have been criticized in recent years for, in fact, spending too much time appeasing promoters and managers. Golden Boy Promotions was given what many felt was a pure sweetheart deal to stage fights on the network, possibly owing to Oscar de la Hoya's years of service as HBO's No. 1 boxing draw. HBO has also been accused of too frequently favoring fighters under the care of manager Al Haymon, such as Andre Berto, who stood out in recent years as a fighter overpaid given his inability to draw fans, both at the gates and on TV, and often facing soft opposition in fights that HBO coveted for whatever reason.

And obviously, losing Manny Pacquiao to Showtime/CBS earlier this year did play a major role. There's no doubt about that.

Dan Rafael has this from HBO, also on Twitter:

Statement from HBO co-presidents Richard Plepler and Michael Lombardo: 'We believe that Ross’ track record speaks for itself. He has helped redefine the sports programming genre and set an extraordinary standard of excellence in the industry. We will miss his leadership, vision, creativity and passion for sports television."

It's definitely worth noting that Greenburg did a lot more for HBO Sports than just boxing, as he was a key figure in many of their acclaimed documentaries, and was behind the "Real Sports with Bryant Gumbel" program, which is well-regarded, as well as "Sports of the 20th Century."

No replacement has been named.