Jackson, 28, signed a one-year, $11 million free-agent contract with the Nationals last offseason after turning down multiyear deals from other clubs. The Pirates offered him a three-year contract for around $30 million, sources said.
The Nationals are Jackson’s sixth team in the past five seasons. He almost certainly will seek a long-term deal if he returns to the free-agent market this offseason.
Jackson has been traded six times, including twice in one day last July 27, going from the Diamondbacks to the White Sox, and then from the White Sox to the Blue Jays.
This season, as part of the Nationals’ powerhouse rotation, Jackson is 5-6 with a 3.73 ERA. He is 40-36 with a 3.92 ERA since the start of the 2009 season and has not been on the disabled list since 2004.
The Legacy partners include Greg Genske, Brian Peters and Scott Parker. They represent New York Yankees left-hander CC Sabathia, Boston Red Sox left fielder Carl Crawford and Chicago White Sox designated hitter Adam Dunn, among others.