ANAHEIM, Calif. -- Second baseman Bill Ripken suffered a strained muscle in his rib cage over the weekend and may have to be placed on the 15-day disabled list.
Precautionary X-rays revealed no structural damage to the rib cage and no sign of lung inflammation, so it appears that Ripken suffered a strained intercostal muscle, perhaps while making a difficult defensive play during the recent four-game series against the Oakland Athletics.
"I don't know exactly when it happened," Ripken said. "I first felt it on the plane from Oakland. It could have been on a ball that [Harold] Baines hit. That was awkward enough to do this, but I didn't feel anything at the time."
Manager John Oates isn't sure how it happened, but he knows that rib cage strains are slow to heal. He said yesterday that the disabled list is a very likely possibility, but would not commit to that until he got further medical information.
"If that's what it is, it'll take a while," Oates said.
If Ripken does go on the DL, it would be the fourth time in the past three seasons.
When he was scratched from the starting lineup on Monday night, it was at first thought that he had aggravated a chronic lower back injury, but the two injuries are not related.
Surgery set for McKnight
Utility player Jeff McKnight was scheduled for an exploratory arthroscopic procedure this week to determine the cause of some instability in his left shoulder.
McKnight apparently has been experiencing shoulder discomfort since spring training, but was hoping to play through it and have it looked into after the season. The wrist injury that forced him onto the disabled list made this an opportune time to investigate the problem.
Dr. James Andrews was scheduled to perform the procedure in Birmingham, Ala.
Opportunity knocks for Bell
The injury to Ripken probably will mean everyday playing time for utility player Juan Bell, who has been languishing on the roster with a loosely defined role.
Bell started in Ripken's place on Monday night and had one of the Orioles' three hits off California Angels starter Kirk McCaskill. If Ripken goes on the disabled list, the club finally will get a chance to see him over an extended period.
"How are we ever going to find out about him if we don't play him?" Oates said. "I'm going to find out. Tim Hulett will play some, but Bell will probably be out there most of the time."
Bell, who went 1-for-3 last night, is batting .147 with no home runs and four RBI. He was hitless in his previous 11 at-bats when he singled in the third inning on Monday night.
Milacki throws without pain
Right-hander Bob Milacki experienced some stiffness in his right hand when he played catch on Monday, but pitched off the mound without pain yesterday.
"It felt good," Milacki said. "I'm fine. I'll pitch Thursday."
Milacki is scheduled to pitch the second game of the brief two-game series against the Kansas City Royals at Royals Stadium.
P Dave Johnson's injury-rehabilitation assignment was transferred from the Class AA Hagerstown Suns to the Class AAA Rochester Red Wings. He will start for the Red Wings tonight in Richmond, Va. . . . Ben McDonald flew to Kansas City, Mo., early so that he would be rested for tonight's start against the Royals.