While remaining open to a trade to add pitching, the Rockies have expressed mild interest in low-risk free agents Brandon Webb and Jeff Karstens.

Bill Geivett, the Rockies' director of major-league operations, said Friday the club plans to watch Webb throw in a week to two weeks in Phoenix as the right-hander attempts a comeback. The 2006 Cy Young Award winner for the Diamondbacks hasn't pitched in the big leagues since facing the Rockies on opening day in 2009.

Webb, 33, was derailed by a shoulder injury and never fully regained the command of what was one of baseball's most devastating sinking fastballs.

After taking time off, his arm has improved along with his arm action, leading him to attempt a return.

The Rockies want to learn more about Webb's health, but they have had success with past reclamation projects Darren Oliver and Shawn Estes — and, to some degree, Jamie Moyer last season.