Leal, 17, went 6-2 with a 2.44 ERA (19 ER/70.0 IP) in 14 appearances (12 starts) for the Dominican Summer League Diamondbacks last season. The 6-foot-3, 180-pound Leal struck out 70 and walked only 11 batters in 70.0 innings, an average of 9.0 strikeouts and only 1.4 walks per nine innings while striking out 6.4 batters per walk issued. Leal also allowed only one home run in 70.0 innings pitched and posted a 0.99 WHIP. He is a native of Carabobo, Valencia, Venezuela.
Castillo, 17, went 2-4 with a 5.40 ERA (28 ER/46.2 IP) in 14 appearances (eight starts) for the DSL Diamondbacks last season. The 6-foot-2, 165-pound Castillo struck out 41 and walked 17 in 46.2 innings pitched, while allowing only three home runs. He is a native of San Feliz, Tachira, Venezuela.
Campana, 26, batted .262 (83-for-317) with nine doubles, one home run, 54 stolen bases, a .306 on-base percentage and a .300 slugging percentage in 184 games with the Cubs covering the last two seasons. He was designated for assignment on February 10.