The St. Louis Cardinals on Tuesday purchased the contract of right-handed reliever Mitch Harris from Class AAA Memphis.
Harris, a graduate of the Naval Academy who attained the rank of lieutenant, replaces outfielder Peter Bourjos, who will be away on paternity leave for tree days.
St. Louis also announced that Memphis outfielder Gary Brown has been designated for assignment, which cleared space for the addtion of Harris on the 40-man roster.
Harris, 29, a native of Ocala, Fla., will be making his big-league debut in his first game. He is believed to be the first U.S. Naval Academy graduate to appear in the majors since pitcher Nemo Gaines did so with the Washington Senators in 1921.
Harris was selected by the Cardinals in the 13th round of the 2008 amateur draft, but due to his military service, did not begin his professional career until 2013.
Harris appeared in eight games for the Cardinals in spring training, compiling a 1.86 ERA in 9 2/3 innings. The 6-foot-4, 215-pounder was 0-0 with a 2.45 ERA and two saves in four games and 3 2/3 innings this season at Memphis.
Harris will wear No. 40.