ProFootballWeekly.com cited a source earlier this week in reporting Williams is "right on schedule, if not a little bit ahead" in his recovery from a torn right patella tendon.
"They were thrilled that he was able to participate in 11-on-11 drills at the mandatory mini, and the medical staff just raves about his work ethic," the source said.
If healthy, Williams adds another dimension to a Cardinals running game that includes fourth-year back Beanie Wells and versatile role player LaRod Stephens-Howling.
Coming off a breakout season, Wells -- also recovering from knee surgery -- is the favorite to remain the starter. But Ken Whisenhunt likes two-RB sets, and Williams should have every opportunity to make an impact in his second season.