SCOTTSDALE, Ariz. -- Noah Lowry attributed his stunning inability to throw strikes to a case of tendinitis between his left thumb and wrist, which impedes his grip on the ball and robs him of control.

Lowry was scheduled to return to San Francisco on Tuesday to consult Dr. Gordon Brody, a hand specialist who works with the Giants. Early Tuesday morning in the Phoenix area, Lowry visited Dr. Gary Waslewski, who made the diagnosis after administering an X-ray and range-of-motion tests. Lowry has been told to treat the injury by resting the affected area for a couple of days, wearing a splint and taking anti-inflammatory medicine.

Although Lowry is expected to miss his next start, which would have been Friday against Oakland, manager Bruce Bochy believes that the 27-year-old will be ready to join the season-opening starting rotation as planned.

Lowry said that he noticed the malady, which manifested itself as "fatigue" in his thumb, about a week ago. He tried to pitch through it, but walking nine of the 12 Texas Rangers batters he faced and throwing three pitches to the backstop Monday prompted him to seek medical help.

Lowry, who displayed his quivering thumb for reporters, took comfort in learning that the injury is apparently not severe and should delay his preparation for the regular season only slightly.

"You never want to have an injury," Lowry said, "but on a scale of one to 10, it's closer to a one or two."

Lowry said that receiving a cortisone shot would be an option if his injury doesn't respond to the initial treatment. He'd prefer to avoid that step, but after missing part of the 2006 season with a right oblique strain and the final month of last season with tightness in his left forearm, Lowry's fed up with inactivity.

And he realized how jarring his performance Monday looked.

"I don't want to miss any more time for me or for [the team]," he said. "But at the same time, not just for myself but for these guys on the field, I can't go through what I went through yesterday. The outing, so to speak, doesn't bother me, but that affects the demeanor around here, in my opinion, and that's not something I want to do. I don't want to affect the team in that way. I'm going to get this thing taken care of and we'll go from there."

Always forthright with reporters, Lowry explained that he didn't address the media after Monday's game because it was still in progress (reporters usually are allowed in clubhouses during Spring Training exhibitions) and he wanted to discuss his injury with Bochy and pitching coach Dave Righetti first.

Spring Training
News and features:
• Giants expect mix-and-match lineups
• Cain fans six in Giants' loss to Mariners
• Giants unhappy with sloppy loss
• Giants' Vizquel set for Minor League action
• Giants' PA voice to work Civil Rights Game
• Mixed results for Giants' Zito in tune-up
Multimedia:
• Spring Training Spotlight: Giants  400K
• Rowand on facing his former team  400K
• Lansford offers Giants status report  400K
• Haft on life without Bonds  400K
• Kline discusses spring  400K
• Correia on his outing  400K
Spring Training info:
• MLB.com coverage  |  Schedule  |  Ballpark  |  Tickets

Lowry resented implications that his lack of control might be a symptom of some mysterious problem, paralleling the downfalls of Steve Blass, Mark Wohlers or Rick Ankiel -- accomplished or promising pitchers who suddenly couldn't throw strikes.

Lowry, the Giants' leading winner in two of the last three seasons, spoke contemptuously of what he called "Ankiel stuff" -- referring to widely held assumptions that the problems of the former St. Louis Cardinals left-hander were psychological.

"That's asinine and a slap in the face for anybody that does know me," he said, "so I wanted to set the record straight. It's something that's going on physically. Mentally, I feel I've been somebody who has been able to deal with anything. This is another bump along the road. It's not what defines me. For anybody who knows me, you know that's not what's going on."

Fellow starter Tim Lincecum maintained utmost faith in Lowry. "He's just too mentally strong to let that stuff get to him," Lincecum said.

In fact, Lowry resisted Righetti's offer to leave Monday's game after the first inning and throw in the bullpen to try to fix his pitching mechanics. Besides, Lowry pointed out that throwing in the bullpen doesn't bother him physically, but pitching at "game speed" does. Admitting to reporters that he was "stubborn," Lowry insisted on returning for the second inning. He was removed after walking the first two hitters he faced.

Typifying his stoicism, Lowry apparently told nobody of his injury until it was confirmed. "I don't think anybody was aware of it," Bochy said.

"It's frustrating, obviously," Lowry said. "You want to compete at the level you know you're able to compete at. Sometimes your body doesn't allow you to do that."