"The first couple of games I had butterflies in my stomach and now it's pretty comfortable," said Jackson, who played first base for Arizona from 2005 until a month ago when outfielder Eric Byrnes suffered a season-ending injury. "I feel like it's kind of like riding a bike."
Jackson was one of the heroes in the D-backs' 2-1 win over the Dodgers on Thursday night, when his throw to the plate cut down Andre Ethier to end the eighth inning.
It's not the first time Jackson has made a defensive transition. Primarily a third baseman the University of California-Berkeley, Jackson was shifted to left in 2003 after being drafted in the first round by the D-backs.
D-backs first base coach Lee Tinsley was the organization's roving outfielder instructor at that time and worked with Jackson.
"He's got some instincts out there," said Tinsley, a former Major League outfielder.
In order to get his bat to the big leagues quicker, the D-backs shifted Jackson to first base during Spring Training in 2005. While he maintains that he is comfortable at first, he has long wanted to play in the outfield.
Now, he and Tinsley are once again working to get him acclimated to left.
"He's made some pretty good adjustments out there," Tinsley said. "The biggest thing for him is stretching his arm out and also stretching his legs out to make him more mobile. He's worked his tail off. I think the next phase will be stretching his arm out and getting a little more length in his arm, but for the most part he's done a pretty good job out there."
The arm motion for an outfielder is much different from that of an infielder. Baseball people refer to needing a "longer" arm motion to get more "length" on a throw.
With that goal in mind, Jackson plays long toss every day to try and build up his arm.
"I think the hardest thing for me is definitely the arm strength just because I've been throwing like a first baseman for three years," Jackson said. "I just have to battle through the soreness."
The throw Thursday gave him two outfield assists in his career. D-backs manager Bob Melvin has made a point of not removing Jackson for defensive purposes late in games to try to help him feel better about himself out there.
"To make a play like this, the deciding play in a game, knowing that he's going to be out there and I'm not going to double-switch for him, that all plays into his confidence," Melvin said. "The one thing he hasn't really been challenged this year so far is a play like that."
Steve Gilbert is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.