Mejia is starting at second base and batting seventh Thursday against the Diamondbacks, Jody Jackson of Fox Sports Arizona reports.

EDGE Analysis

St. Louis' demotion of Aledmys Diaz opens up time in the middle infield for the 26-year-old Mejia, who isn't thriving at the plate this year (.251/.305/.366 with three home runs in 251 plate appearances for Double-A Springfield) but will get a tryout.