St. Louis' system will be without one of its top young arms for much of next season.

NEW YORK -- St. Louis Cardinals right-hander Alex Reyes, one of the top pitching prospects in baseball, was suspended for 50 games under baseball's minor-league drug program following a second positive test for a drug of abuse on Monday.

Reyes said in a statement he tested positive for marijuana.

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''I take full responsibility for my actions and apologize for disappointing my family, fans, teammates and the St. Louis Cardinals organization,'' he said. ''I acknowledge my inappropriate behavior and will accept the consequences.''

Reyes had been with the Surprise Saguaros of the Arizona Fall League and will miss the rest of the AFL season, the commissioner's office said Monday.

The 21-year-old right-hander was 5-7 with a 2.49 ERA in 22 starts at rookie, Class A and Double-A this season. He struck out 151 in 101 1/3 innings and regularly pushed his fastball over 100 mph.

There have been 95 suspensions this year under the minor-league program, including 37 for drugs of abuse.