The Royals promoted Wallace from High-A Quad Cities to Double-A Northwest Arkansas on Monday.
Wallace will be making the jump to Double-A this week along with two of the Royals' other top position prospects in outfielder Gavin Cross and middle infielder Javier Vaz. Over 428 plate appearances at Quad Cities this season, the 22-year-old third baseman slashed .261/.341/.431 with 10 home runs and 15 stolen bases in 97 games.