"I'm 100 percent now and trying to get back into baseball and playing shape because I missed three weeks," Jackson said Sunday before his workout with the Rookie League team.
The injuries couldn't have come at a worse time. The Cubs have needed outfield help because of injuries to David DeJesus (sprained right shoulder), Ryan Sweeney (fractured rib), and most recently Brian Bogusevic (hamstring). Junior Lake, who has played more games at third base than outfield in the Minor Leagues, was called up on Friday and has started the last three games in center field. DeJesus made his second start Sunday for the Rookie League team and could be activated from the disabled list by the end of the week.
The Cubs will be playing in Phoenix against the D-backs, opening a four-game series on Monday. Jackson could've been on the big league roster if he was healthy and producing.
"You can let that frustrate you, but it is what it is," Jackson said about the missed opportunities. "I have no control over that. In a perfect world, I wouldn't have been hitting the way I was, been injured the way I have been, the same way [the other outfielders] would prefer not to be injured themselves. It is what it is, and you keep pushing forward, upward and onward, and get into shape and get back into games."
Last Aug. 5, Jackson was promoted to the Cubs' big league team, and batted .175 in 44 games. He spent time with Chicago manager Dale Sveum in October working on his swing to cut down on the strikeouts -- he led the Pacific Coast League with 158 K's in 106 games in 2012. This season, he was batting .223 before he was injured and had six home runs, seven doubles, three triples, 23 RBIs, and 77 strikeouts in 215 at-bats.
When Jackson is ready to play, he could be assigned to Double-A Tennessee rather than rejoin Iowa.
"I'm willing to do whatever it takes to better myself as a player and get back to the big leagues and help the team," Jackson said. "If going back to Double-A is what the team thinks is the right move for me, I have my faith in that decision. To me, it's baseball and all about getting healthy and back into the shape as a player to have success and help the team win at the top."
Right now, he'd just like to play anywhere.
"I've missed more time than I would've liked this year to nagging injuries," he said. "I'm ready to be 100 percent and playing like I'm capable of."
The center fielder is still young -- he turns 25 on Aug. 2 -- and is a valuable left-handed bat with speed. He began this season with a career Minor League average of .282.
For now, he's working out with the Cubs' most recent first-round pick, Kris Bryant.
"I'm just trying to stay positive and keep moving forward regardless of what's happened this year," Jackson said. "I still believe in myself and still believe I can help the team."