Following in the footsteps of ESPN Local and CBS Sports, Comcast will develop local sports sites on the back of its existing TV properties. Comcast has already launched Comcast SportsNet New England, which it calls “the most comprehensive and dedicated online local sports destination.” The site features local media celebrities and has added 40 new positions– a remarkable investment. ESPN and CBS have only added a few new positions at this point.

The New England site is acting as the template for similar upgrades in San Francisco, DC/Baltimore and Chicago. Philadelphia, which upgraded earlier this year, is being run with a different look.

The overall effort is being led by Comcast Sports Net Chief Digital Officer Eric Grilly, former head of Philly.com and longtime leader of MediaNews Group’s digital efforts. Grilly told Sports Business Journal, which we saw via paidContent, that the sports effort is “the single largest investment outside of making an acquisition in the business.”

Grilly also said that Comcast will start “with beat writers for every professional team in the market, then expanding to local colleges and high schools.” Later, it will add lifestyle and entertainment sections. Some of the Web programming is likely to migrate to TV, he added, such as post game shows. The sports upgrade is likely to be further enhanced if Comcast succeeds in its pursuit of NBC Universal, and its owned and operated stations.

ESPN Local SVP Jim Pastor is a featured speaker at ILM:09, Dec. 9-11 in Los Angeles.