Starling announced his retirement Tuesday, Alec Lewis of The Athletic reports.
Starling signed a minor-league contract with the Royals on Saturday.
Starling was non-tendered by Kansas City on Wednesday.
Starling was placed on the 10-day injured list Wednesday with right lower-back spasms.
Starling will sit for the second straight game Wednesday against Cleveland, Alec Lewis of The Athletic reports.
Starling is not in Tuesday's lineup against Cleveland.
Starling went 1-for-2 with a solo home run and a walk in Saturday's 5-3 loss to the White Sox.
Starling came off the bench to deliver a pinch-hit RBI single in Monday's 2-1 win over the Indians.
Starling (undisclosed) returned from the injured list Friday.
Starling (undisclosed) could return from the injured list for this weekend's series against the Twins, Jeffrey Flanagan of MLB.com reports.