Sony, Microsoft and Nintendo: These are the big names fighting it out to win over gaming console consumers. But speculation is building that now there is another.

Citing unnamed “people familiar with the matter,” the Wall Street Journal reported Thursday that Google is working on a game console.

Google declined to comment on the report, which also said the company is working on its own Android-based wristwatch and a second version of its never-launched Nexus Q streaming-media player.

The news comes as the traditional big three of the console world strive to adapt to a changing gaming market, each with its own particular strategy. Microsoft, for example, is taking pains to market its forthcoming Xbox One as a holistic entertainment system to please gamers and non-gamers alike, while Sony is doubling down on offering deeper gaming features that appeal directly to console gamers. Nintendo, meanwhile, is focusing on family gamers and integrating its Wii U console and tablet-like gamepad controller into the entertainment systems that people already own.

As for Google, it’s already a key player in the gaming space. According to the Entertainment Software Association’s 2013 U.S. profile of who’s gaming these days, an average of 58 percent of Americans play video games. Of that chunk, 36 percent play games on their smartphones while a quarter play on their wireless devices.

With its smartphone dominance, Google is sitting pretty in $20.77 billion gaming market. And the possibility that the tech giant will launch a direct competitor should be enough to make executives at the big three break into a cold sweat.

Google would also be responding to demand for better mobile — or at least portable — gaming experiences. Gaming on tablets has particular potential for supplanting dedicated handheld gaming devices such as the PlayStation Portable or Nintendo 3DS. But the offerings so far haven’t been that strong, plagued by game lag or simply the inherent limitations of a smaller screen.

If Google can make its mega successful Android platform hit gamers at home and on-the-go, it could fill a major hole in the gaming world.

Android’s open system has already provided ways for independent developers to launch their own small gaming projects. And the Android ecosystem got a boost with the introduction of systems such as the Ouya, which has earned support for its vision of providing TV-accessible Android-based games.

Still, apparently there are some bugs to be worked out in the new systems. Ouya has drawn early negative reviews for shipping a console with hardware and software that critics say weren’t quite ready for prime time. Another Android-based gaming system, the Nvidia Shield, has hit hardware problems of its own that forced it to delay its retail launch until next month.

Related stories:

Google to use balloons to provide free Internet access to remote or poor areas

OUYA: CEO looks to future as console launches

Sign up today to receive #thecircuit, a daily roundup of the latest tech policy news from Washington and how it is shaping business, entertainment and science.