Seattle - Don Mattingly is experiencing back problems again, and the spasms that forced him to leave Thursday afternoon's game could sideline him for the rest of the series with the Mariners. Maybe longer.

"Until they break, we won't know the severity," Buck Showalter said. "I don't expect him to play any more this series."

Mattingly experienced spasms in the lower right area of his back during batting practice Thursday but still started at first base. He aggravated the condition swinging at a two-strike pitch in the second inning, popping up to shortstop, but was not replaced by Russ Davis until the top of the fourth.

It was only the fifth time in Mattingly's career that he has been replaced by a pinch hitter. Dion James played first base last night for the first time since 1990.

Mattingly described the injury as "tightening" of the back muscles but was not overly concerned yesterday. "As soon as they clear," Mattingly said, "I should be all right."

In 1990, Mattingly was placed on the DL and missed 47 games because of recurring back spasms and lower back pain. David Lennon

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