ST. LOUIS -- The St. Louis Cardinals have demoted struggling rookie Kolten Wong to the minors.

Wong, the starting second baseman to open the season, and reserve outfielder Shane Robinson were optioned to Triple-A Memphis on Monday. Rookies Greg Garcia and Randal Grichuk, both off to strong starts, were recalled from Memphis and are in the majors for the first time.

The 23-year-old Wong was batting .225 with five RBIs in 71 at-bats and didn't play the last two games of a weekend series against Pittsburgh. Robinson was batting .100 with no RBIs in 20 at-bats.

Mark Ellis will start at second base for the Cardinals.

Garcia was batting .267 at Memphis with a team-leading five home runs and three triples while starting at second base. Grichuk, acquired from the Angels last offseason, was batting .310 with a team-leading 17 RBIs and 16 runs.