Lopez, 28, was batting .210 with three triples and 13 RBIs in 67 games for the Royals this season. In five seasons, all in Kansas City, he is a career .248 hitter with five home runs and 119 RBIs with 15 triples and 40 steals.
Lopez is considered an above-average fielder at second base and shortstop.
Hearn, 28, had just one outing with the Braves after his contract was purchased from the Texas Rangers on Monday. He has a 14.73 ERA in five outings with the Braves and Rangers this season. In 93 appearances (25 starts) over five big league seasons, mostly with Texas, Hearn is 12-15 with a 5.26 ERA.