Webb's agent, Jonathan Maurer, tells the Pittsburgh Post-Gazette 's Dejan Kovacevic that the Pirates are "one of a number of teams that are interested."
CBSSports.com has learned as many as 10 teams have expressed interest in Webb. Reports have tied the Nationals and Cubs to Webb, while the Rangers, Rockies and Twins are among other suitors.
Webb, 31, won the Cy Young in 2006, but hasn't pitched since opening day of 2009, when he suffered a shoulder injury.
Webb pitched for the Diamondbacks in an instructional league game in October, throwing in front of a reported 21 teams. He topped out at 85 mph in that outing, but Maurer said his client was "about 75-80 percent of his usual strength."
-- C. Trent RosecransFor more baseball news, rumors and analysis, follow @cbssportsmlb on Twitter or subscribe to the RSS feed.