Campana had seen the writing on the wall.
"When you have eight outfielders on the (40-man roster) and you sign another outfielder, you know one of you is probably going to go and I was the one," Campana said. "I'm glad there is a team out there that wanted me enough to trade for me. That's cool.
"You have to perform when you get up here. I was able to in spurts but just not enough."
Campana, 26, hit .264 with 30 stolen bases last season for the Cubs but was designated for assignment earlier this month.
"It's difficult to lose Tony from the organization," general manager Jed Hoyer said. "He's a great person, he's a fantastic base stealer ... but ultimately you can only protect 40 guys on the roster and he got caught up in that roster crunch. We have some depth in the outfield, we have less depth in pitching."
In return for Campana the Cubs got right-handed pitchers Erick Leal and Jesus Castillo. Both are from Venezuela.
"We did a lot of work with our scouts down in the Dominican Republic," Hoyer said. "We feel good about getting two projectable arms."
Leal went 6-2 with a 2.44 ERA in 14 appearances (12 starts) for the Dominican Summer League Diamondbacks last season. He struck out 70 and walked 11 batters in 70.0 innings.
Castillo went 2-4 with a 5.40 ERA in 14 appearances (eight starts) for the DSL Diamondbacks last season. He struck out 41 and walked 17 in 46.2 innings pitched, while allowing only three home runs.