The deals include invites to major league spring training.
Lopez, 31, has a 16-17 record with a 3.54 earned-run average through 305 1/3 innings spanning six major league seasons. He pitched 6 1/3 innings with the Colorado Rockies last season, giving up eight runs on 18 hits while striking out four batters.
Gindl, 26, played in eight games for the Milwaukee Brewers in 2014, batting .158 with a .304 on-base percentage. He was drafted by the Brewers in the fifth round of the 2007 draft.
Fox, 32, split last season between the Philadelphia Phillies' double-A and triple-A affiliates, batting .307 in triple-A and .308 in double-A. He also spent five games playing independent league ball for the Somerset Patriots in New Jersey.
Fox last played in the major leagues with the Baltimore Orioles in 2011, racking up 15 hits — including four doubles, a triple and two home runs — in 27 games.