EA Sports, which ended publication of Madden NFL for the PC in 2008, evidently had plans to return to that platform through a browser-based game sometime in 2010, according to mockups created by a former staff designer. The label was serious enough about the project to build a working, mouse-driven interface for the game's console engine.
The work came to light through the personal web site of Matt Metropulos, an EA Sports veteran who is leaving the company (and whose farewells to, and well wishes from, EA Tiburon staff, were noticed on Twitter yesterday.) Metropulos says Madden NFL Online was meant to be "a social site complete with a fully playable game."
I ran this by sources close to EA Tiburon who said that, yes, Madden NFL Online was definitely an initiative, not some whiteboard rumination. It was shuttered for a couple of reasons. The first is that at the time, they hadn't figured out how to stream the essential code and components to the players; it would have required a download in excess of 4 GB, a major barrier to broad audience pickup.
The second is that other initiatives were brewing with Tiger Woods PGA Tour, which launched in 2010, and FIFA Online, which came west in a beta release that year. For whatever reasons, either in terms of market potential or technical compatibilities, they were better bets than 11-on-11, simulation quality American football.
Those who worked on Madden NFL Online were repurposed to projects such as Madden Ultimate Team (a mode included with the console game), Madden NFL Superstars (a Facebook game), and Madden NFL Arcade (a 2009 downloadable release that earned a mixed critical reception.) Madden NFL has iterations on all consoles and major mobile platforms, but none on PC today.
Later in 2010, QuickHit Football became QuickHit NFL Football, a free-to-play football strategy simulation with official league licensing. QuickHit is a play-calling and team-management game, rather than one focused on executing the plays, yet it does not have the licensing of the NFL Players Association, so it cannot use fully realistic rosters. Who knows what Madden had envisioned in its gameplay engine, but QuickHit's movement into this space, as an official league partner, probably guarantees we won't see Madden NFL Online anytime soon.