Roy Dabner, Associated Press Oliver Perez allowed eight runs and 10 hits in his last start -- an 8-4 loss to the Diamondbacks in Arizona that dropped his record to 1-4. Click photo for larger image.

SAN FRANCISCO -- The Pirates scratched Oliver Perez from his scheduled start today because of what management and Perez are describing as stiffness in his throwing shoulder.

He will not pitch again until, at the earliest, next Tuesday or Wednesday at PNC Park against the Chicago Cubs.

"It makes all the sense in the world to get him some time to recuperate," manager Lloyd McClendon said. "Hopefully, when he comes back, we'll have the old Oliver."

Perez, the staff ace last season, is 1-4 with an 8.03 earned run average.

He said he first felt the stiffness about two hours after his most recent outing, Friday in Phoenix. He allowed eight runs in 5 1/3 innings in an 8-4 loss to the Arizona Diamondbacks.

"The next day, I was feeling the same," Perez said. "I could not sleep."

The Pirates' medical staff has tested Perez since then, McClendon said, and determined that his strength and flexibility measurements are "no different at all" from the ones taken at the end of last season.

Perez said the discomfort was not similar to the shoulder stiffness that caused him to miss the first 12 days of spring training. He and the team attributed that ailment to Perez sleeping awkwardly on his shoulder.

"This is new," Perez said. "I didn't feel anything until my last start."

Perez tried a long-toss session Sunday, but he was shut down early after showing some discomfort.

He threw again from 90 feet yesterday and said he felt "great." That allowed the team to schedule another bullpen session for Friday.

Perez and pitching coach Spin Williams were adamant that the shoulder is not why Perez's velocity has been down 4-5 mph from the peak of 97-98 mph he reached last year. Williams said he studied tapes from early in the 2004 season and saw that Perez's velocity was about the same as it has been to this point this season.

The root of the velocity dip, Williams said, is that poor command has forced Perez to try to be too fine.

"He'll get in trouble and start walking people, and then he backs off to try to keep the ball in the strike zone," Williams said. "It's hard to flip the on-off switch to go from 88 mph to 92 or 93."

Perez's confidence, he added, has diminished.

"He started off slowly, got hit around his first couple of outings, and he's been pressing more and more every time out. That creates overthrowing, and overthrowing creates lack of command. And those two things create his tenderness."

Williams' plan is to use Perez's down time to work on every aspect of Perez's delivery and approach, just as he did with exemplary results before last season.

"It's going to take time," Williams said. "Ollie wants it to come right away, but it doesn't happen like that."

Wilson has surgery

Outfielder Craig Wilson's finger surgery yesterday morning at Allegheny General Hospital resulted in no new prognosis.

Dr. Mark Baratz, the Pirates' hand specialist who performed the operation, estimated that Wilson will wear a splint for 3-4 weeks, then rejoin the lineup in 6-8 weeks. That has Wilson on track to play again close to the beginning of July.

Baratz repaired torn tissue above the middle finger of Wilson's left hand, which was injured during a swing Friday in Phoenix.

North Side notches

Josh Fogg will take Perez's spot today despite having only three days' rest. Because Fogg made only 88 pitches Saturday, McClendon decided to use him instead of reliever Ryan Vogelsong. McClendon expects to use Fogg no more than five innings.

In their 32nd game, the Pirates finally fielded a lineup they used previously. The starting eight last night was the same as the starting eight Sunday in Phoenix.