Morgan was outrighted to Nashville on Thursday. He hit .304 while helping Milwaukee win the NL Central in 2011, but slumped to .239 this year and the Brewers failed to make the playoffs.
Ishikawa batted .257 with four homers and 30 RBIs in 94 games in his first season with Milwaukee.
Leon has never pitched in a major league game. He was 3-2 with a 4.38 ERA in 44 games for Double-A Corpus Christi this season.