NEW YORK — Detroit pitcher Drake Britton has been banned for 50 games following a positive test for amphetamine under baseball's minor league program and St. Louis second baseman Luke Doyle has been suspended for 100 games for refusing to take a test.

Britton, a 27-year-old left-hander, made 25 relief appearances for the Boston Red Sox in 2013 and '14, going 1-1 with a 2.93 ERA. He is 0-3 with a 4.57 ERA this year in 37 relief appearances for Triple-A Toledo.

The 21-year-old Doyle, a 20th-round draft pick last year, is hitting .207 with three homers and 25 RBIs for Johnson City of the rookie level Appalachian League.

The commissioner's office announced the discipline Tuesday. There have been 63 suspensions this year under the minor league drug program and 13 under the major league program.