The moves were made before Monday night's game against the San Diego Padres.
LeMahieu was hurt Sunday while taking a swing during a loss to Milwaukee. He was batting .279 with five home runs and 13 RBIs. The two-time All-Star and Gold Glove winner also was on the DL from April 30 to May 8 with a strained right hamstring. He had never been on the disabled list prior to this season.
Valaika, who played at UCLA, made his first career opening-day roster before being optioned to Albuquerque on May 8. He hit .103 with one RBI during his first stint with the Rockies.