When his team, the Portland Timbers, debuts in 2011 it will set up a regional rivalry with the nearby Seattle Sounders, new to the league this year, and the Vancouver Whitecaps, also set to join MLS in 2011.
The Sounders kicked off the 2009 MLS season on Thursday with an emphatic 3-0 victory over the New York Red Bulls, who lost the championship match last year to the Columbus Crew.
More than 32,000 raucous fans showed up at Qwest Field in Seattle to watch the return of professional soccer to the city, suggesting that soccer has its die-hard followers in the U.S. Northwest despite the faltering economy.
Portland will play games at PGE Park, now home of the Portland Beavers, the city's Triple-A minor league baseball team. Earlier this month Portland approved plans to build a new stadium for the Beavers.
Both the Timbers and the Beavers are run by Shortstop LLC, which is majority-owned by Paulson, a Portland local who was previously in charge of marketing and business development for the National Basketball Association.
His father, Henry "Hank" Paulson, the former Secretary of the Treasury for President George W. Bush, has a minority stake in Shortstop.
The MLS did not say how much Paulson's company paid for the soccer franchise.
