Struggling shortstop Aledmys Diaz was optioned to Class AAA Memphis by the St. Louis Cardinals on Wednesday, prior to their game against the Arizona Diamondbacks.
The Cardinals purchased the contract of infielder Alex Mejia from Memphis. Mejia was batting .263 with three RBIs in 11 games with the Redbirds after starting the season at Class AA Springfield, where he batted .251 with 17 doubles, three homers and 24 RBIs in 63 games.
To make room for Mejia on the 40-man roster, the Cardinals moved pitcher Alex Reyes (Tommy John surgery) to the 60-day disabled list.
Mejia, 26, was selected by the Cardinals in the fourth round of the 2012 draft (150th overall) out of Arizona. He is a right-handed hitter who recently was selected as a Texas League All-Star.
Diaz, 26, finished fifth in National League Rookie of the Year balloting last season for the Cardinals, batting .300 with 28 doubles, 17 home runs and 65 RBIs in 111 games.
Diaz, however, has been unable to match that production this season. He is batting .260 with 16 doubles, seven home runs and 20 RBIs in 71 games, with a .293 on-base percentage.
Diaz, who lacks range, has committed six errors on 234 chances, a .974 fielding percentage.
Mejia has been assigned No. 54.