The 26-year-old outfielder, a career .244 hitter in eight minor league seasons, is hitting .310 this season in his first full season with Triple-A Omaha, with seven home runs and 38 RBIs in 72 games.
Several established major leaguers were selected after Starling in the 2011 draft, including Anthony Rendon (No. 6), Archie Bradley (No. 7), Francisco Lindor (No. 8), Javier Baez (No. 9) and George Springer (No. 11). Gerrit Cole was the No. 1 overall pick that year and Trevor Bauer went No. 3 overall.
Starling was non-tendered by the Royals last November but re-signed with the organization in December.
The Royals said they will announce a corresponding move on Friday before their game against the Detroit Tigers.