"[It] went good," Webb told MLB.com. "[The] ball came out well, but I was just thinking about arm slot on every throw. That's to be expected, not having thrown on the mound in so long."
Webb made just one start in 2009 because of shoulder discomfort. On Aug. 3 he underwent a minor procedure known as a debridement to clean up some fraying around the labrum.
"It was good to get him into the next phase of his rehabilitation," D-backs manager A.J. Hinch said. "He looked comfortable. This is a positive sign as we're getting close to Spring Training. I thought he looked good."
Webb began playing catch for the first time post-surgery in mid-November. He threw four times without experiencing any discomfort before shutting things down for two months.
Webb had been playing catch again for weeks before getting on the mound on Tuesday.
The club will be cautious with Webb this spring, possibly giving him extra days' rest between throwing sessions. The right-hander has said that if things keep progressing as they have, he does not see any reason why he would not be ready for the start of the season.
Steve Gilbert is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.