Randy Johnson threw off a mound today:

Arizona left-hander Randy Johnson reported no problems after throwing off a mound Friday morning for the first time since October back surgery.

Johnson said he felt "pretty free and easy" throwing 25 fastballs.

"I'm feeling a lot better than I did the last time I picked up a ball, let's put it that way," the 43-year-old Johnson said.

The last time Johnson underwent back surgery he came back to post a 20-4 record with a 2.28 ERA (his best year by the ERA+ method). That was ten years ago, but if the surgery can even shave a run off his 2006 season, he'll be a successful pitcher for the Diamondbacks.