TUCSON, Ariz. -- Arizona Diamondbacks third baseman Chad Tracy took a big step in his rehabilitation Sunday.
Make that several big steps.
Tracy, recovering from microfracture surgery on his right knee, went through agility drills on a side field at Tucson Electric Park. The workout was viewed as a milestone in Tracy's long road back.
"Today was the day that I feel like you get over the hump and you start back on the good side," Tracy said. "I know now that I'll be ramping up the intensity every time out."
Tracy hopes to speed the process with a special treadmill -- expected to arrive Tuesday -- that will allow him to exert himself without putting full weight on the knee.
Tracy still hasn't run, and the club doesn't know when he'll be able to play in a spring training game. But manager Bob Melvin was encouraged by Tracy's workout.
"It's a step where he's actually done something with his legs," Melvin said. "Now at least the clock's started on him to where each and every day you do a little bit more. Hopefully we're going in the right direction."
Tracy wasn't the only injured Diamondback to make strides on Sunday. Left-hander Randy Johnson, returning from back surgery, threw 26 pitches off a mound and could be ready to face hitters in his next outing, tentatively scheduled for Thursday.
"We're going kind of outing to outing with it so we don't get too far ahead of ourselves," Melvin said. "We've had no setbacks."
The Diamondbacks don't have a timetable for the 44-year-old Johnson's first regular-season start. The same is true for Tracy, who hopes he'll be ready when the Diamondbacks open the season at Cincinnati on March 31.
"The goal is opening day," Tracy said. "I also realize that this injury is not something you can rush, and it can easily be set back.
"For me, the bottom line is no setbacks," he added. "You try to get out there sooner and you end up coming back a lot later."
If Tracy is delayed, the Diamondbacks have insurance in outfielder Trot Nixon, who is in camp on a minor league contract. Nixon, who has been working out at first base, could provide a left-handed bat off the bench.
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