MESA, Ariz. - Mark Prior took the first step Monday in his comeback from a strained right-shoulder muscle. The big question is whether he took that step from square one or somewhere beyond that.
Prior met with the Cubs' medical staff Monday morning and got clearance to begin throwing again. The star right-handed pitcher then went out and played catch from about "60-70 feet," throwing about 30 tosses.
The Cubs will increase the intensity of Prior's work every day, but they refuse to put any timetable on when he might pitch in any kind of a game.
"I felt good throwing and didn't have any symptoms," Prior said. "I was happy with the way I threw the ball. I didn't throw a lot, just playing catch, but it felt good."
What Prior does from here depends on how he feels each day after he throws.
"I don't know, and I won't know probably for another few days until I start stretching out and seeing where I'm at," he said. "I only got back to 60-70 feet. They wanted me to stay at a short distance. So I probably won't know that until I get back to 100-110 (feet) and see how it's coming out.
"I don't think I'm at square one, but how far in front of square one, I don't know. So I think that'll be determined once I get going and seeing how I feel and once I get on the mound to see where I'm at with arm speed up there."
The 25-year-old Prior already was on a slower program this spring because the Cubs said they wanted to avoid the elbow problems that plagued him the past two spring trainings.
Prior last threw from a bullpen mound March 12. Two days later, he said his shoulder hurt him while he was preparing to throw from the mound again that day.
The Cubs sent Prior for an MRI arthrogram, which revealed a "moderate strain to the subscapularis muscle," or the muscle under the armpit that's attached to the underside of the shoulder blade. The subscapularis is part of the rotator-cuff group of muscles. Doctors prescribed a rest period of 7-10 days.
Even though Prior is throwing again, albeit lightly, the Cubs won't rush him.
"We see how he reacts and we just increase the activity as he tolerates it," trainer Mark O'Neal said. "But it's not anything we're going to be very aggressive with because this is like a hamstring.
"Obviously, it hasn't healed completely 100 percent. If you were to do an MRI on it, you'd probably have some inflammation still in there. So we've got to be real careful and try to strengthen it as it heals."
The Cubs need Prior, as well as starters Wade Miller and Kerry Wood, both of whom are recovering from shoulder surgery.
It's possible Wood could be back by late April, and perhaps Miller could follow him two weeks later. With Prior, it's anybody's guess, but pitching coach Larry Rothschild said he does not believe Prior is back to square one.
"He probably threw a little more than we intended when he got out there, but he felt good," Rothschild said. "We'll see how he reacts to the throwing (today).
"I'll pretty much go by what the doctors say at this point and try to get him through the first three or four times throwing and then decide where he is and how much of a setback the two weeks has been as far as arm strength and stamina and things like that, and try to build him up without it taxing it too much. To build it up, you have to get to points of where he's tired."