The Royals make a minor trade, moving a third baseman Emmanuel Rivera to the Diamondbacks for pitcher Luke Weaver. The real reason for the trade was to make room for rookies:

The 26-year-old Rivera was hitting .237 with six homers and 22 RBI in 63 games for the Royals this season. But he was mostly used as a backup in Kansas City, and his trade could mean a move back to third base for elite youngster Bobby Witt Jr. and more time in the lineup at shortstop for rookie Maikel Garcia.

ESPN.com

Garcia is six for his first 16 in the majors, while Witt showed impressive power so far. Those two might be playing next to each other for a long time.