Valera, 26, hit .314/.368/.450 in 117 games in Triple-A Memphis in 2017 and was 1-for-10 in his brief stint in the majors with St. Louis. In addition to second base Valera has played third base, shortstop and all three outfield positions in the minors. St. Louis signed Valera out of Venezuela in 2010.
“I see that he’s versatile and can run. He has the ability to get on base and doesn’t strike out a whole lot. He’s pretty interesting,” manager Dave Roberts said. “At 26 he’s on the cusp of making a breakthrough, so hopefully he gets an opportunity.”
Valera was designated for assignment by the Cardinals on Wednesday.
The Dodgers will option Valera to Triple-A Oklahoma City, whose season opens on Thursday afternoon at Iowa.
Mieses, 22, was the Dodgers’ 36th-ranked prospect heading into 2018 by out David Hood, and hit .215/.293/.449 with 24 home runs between Class-A Rancho Cucamonga and Double-A Tulsa in 2017.
“Mieses is a terrific defender with range and a plus arm, but he failed to make contact often enough in Double-A Tulsa to tap into his plus raw power consistently,” Hood wrote in December, “but [has] valuable secondary tools if [he] can improve at the plate.”
St. Louis assigned Mieses to Class-A Palm Beach.
Valera has 18 days of major league service time and has two option years remaining, having used an option in 2017. The Dodgers’ 40-man roster is now full.