Webb's agent, Jonathan Maurer, said that the right-hander has been asked by fans as he's traveled recently whether he was planning on pitching in the Classic, so Maurer drafted a statement on behalf of his client.
"While I am excited for Team USA and the [Classic], I am not going to participate in 2009 because I want to fully prepare for the 2009 Major League season," Webb said in the statement. "We came up just short of the playoffs last year, and my focus and efforts are in seeing that we bring the playoffs back to Arizona."
The 29-year-old was 22-7 last season with a 3.30 ERA, finishing second in the National League Cy Young Award voting. It was the second straight year in which Webb finished second after capturing the award in 2006.
Webb has been a workhorse for the D-backs, throwing more than 200 innings in all five of his full seasons in the Majors. In 2003, his rookie season, he was called up in May and threw 180 2/3 innings in 28 starts.
The Classic begins in Tokyo on March 5, and runs through March 23.
Steve Gilbert is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.