The Royals designated Waters for assignment Wednesday.
Waters had his contract selected from Triple-A Omaha on Tuesday and is already back off the 40-man roster with Michael Massey being activated from the concussion injured list. Waters has slashed .251/.312/.420 with 12 home runs, 49 RBI, 58 runs scored, 17 stolen bases and a 32:101 BB:K at Omaha this season.