The Kansas City Royals (41-47, 45-43 RL, 34-53-1 O/U) take on the Arizona Diamondbacks (43-44, 41-46 RL, 45-37-5 O/U) in the second of a three-game series on Saturday evening, and we have you covered with the prediction. The Royals are going with Michael Wacha. The Diamondbacks will reply with Ryne Nelson. The Diamondbacks went 2-1 against the Royals last season. Can Nelson earn his fifth win of the season for the Diamondbacks? Check out the Royals vs. Diamondbacks prediction.