Also reassigned to Minor League camp were right-handers Tyler Cloyd and Ben Meyer, along with catcher Rodrigo Vigil and infielders Johnny Giavotella and Jonathan Rodriguez.
None of the moves are a surprise.
Harrison, who was not on the 40-man roster, was acquired from the Brewers in the Christian Yelich trade. In nine Grapefruit League appearances, Harrison had 15 at-bats, batting .133 with two doubles and three RBIs. He is refining his swing, and he projects to open at Jacksonville or Class A Advanced Jupiter.
Neidert, Gallen, Gonzalez and Lopez were acquired in trades either in the offseason or dating back to last July. Richards is a homegrown prospect who finished up last year at Jacksonville, and he could wind up at New Orleans.