FORT LAUDERDALE, Fla. -- It happens every spring.

Just when you think a pitching staff is set, injuries take a toll. A team opening the season without a pitcher on the disabled list is as rare as an April without a rainout.

And the Orioles can only hope they haven't been hit big time.

First it was Ben McDonald, the scheduled Opening Day starter who had been penciled in to pitch six of the first 21 games, who went to the sidelines. Now it appears that ace reliever Gregg Olson, who set a club record with 37 saves last year, could open the season on the sidelines.

Olson, who was shut down for three weeks last year with a tender elbow, is bothered now by a sore right shoulder. He has been scratched from further participation in exhibition play and his availability for Monday's season opener is uncertain.

"I'll be ready," said Olson. "All I need is a couple of days." He said the injury, on the under side of the arm near the shoulder, developed Monday after he had pitched an inning against the Yankees the day before.

"I didn't get real loose," said Olson, "and the next day I work up with some stiffness." He said the problem was in an area that hadn't bothered him before, one reason he felt a few days' rest would be sufficient.

The irony of Olson's situation is that manager Frank Robinson had purposely held him back this spring in an effort to preserve his arm. Olson has pitched 11 innings this spring, but that is only two fewer than he had thrown two years ago when he originally earned a spot on the roster.

"We'll wait and see how he feels after throwing Saturday," said Robinson. "But if he says he'll be ready, then I think he'll be ready."