The 26-year-old outfielder, a career .244 hitter in the minor leagues, is hitting .310 in his first full season with Triple-A Omaha, with seven home runs and 38 RBIs in 72 games.
Starling spurned a scholarship offer to play quarterback at Nebraska to sign with the Royals in 2011, receiving a $7.5 million bonus -- then the second-largest in draft history and the most guaranteed money to a prep player.
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.
Royals general manager Dayton Moore told MLB.com that Starling will not ride the bench when his years-in-the-making arrival happens. But how much he plays ultimately will be up to manager Ned Yost, who has had plenty of opportunities to observe Starling the past few springs.
"This is a celebration for what he has earned," Moore told MLB.com. "He has had three solid months of production and good health. We look forward to his arrival."
The Royals said they will announce a corresponding move on Friday before their game against the Detroit Tigers.
The Associated Press contributed to this report.