Nick Johnson missed the entire 2000 season with a strained muscle in his right hand.
He would miss the remainder of the season with a torn pectoral muscle.
Lopez was a sensation last year, winning 15 games as a rookie, but he missed six weeks earlier this season with a strained oblique muscle.
O'Neal will miss the opener with a pulled abdominal muscle.
Alfonzo was activated tonight off the disabled list after missing 19 games with a strained oblique muscle in his left side.
Valenzuela missed nearly two months last season with a stretched muscle in his left shoulder, and won only five games.
Johnson missed the 2000 season with a strained muscle in his right hand, but he said this injury was not similar.
Franco missed two weeks with a sore pectoral muscle before returning on Tuesday, and he felt no discomfort today.
Carlos Baerga did not play tonight; he has missed four straight games with a strained abdominal muscle.
But Mitchell will miss a fourth straight game with a pulled back muscle.