The 31-year-old Lopez is 16-17 with a 3.54 earned-run average in 305 1-3 innings in six major league seasons. He pitched 6 1-3 innings for Colorado last season.
The 26-year-old Gindl appeared in eight games for Milwaukee this year, batting .158 with a .304 on-base percentage.
The 32-year-old Fox split last season between Philadelphia's Double-A and Triple-A affiliates, batting .307 in Triple-A and .308 in Double-A. He last played in the majors with Baltimore in 2011.