Vitters, the Cubs' No. 1 Draft pick in 2007, was batting .300 after 108 games with Iowa with 16 home runs, 31 doubles, two triples and an .857 OPS, while Jackson, the top pick in '09, was hitting .258 in 104 games with 15 home runs, 22 doubles, 12 triples and an .824 OPS.
Jackson also has struck out 154 times. However, the team saw positives when Cubs hitting coach James Rowson saw Jackson in May. At that time, Rowson was the Cubs' Minor League hitting coordinator.
"He was having some punchouts, and then he made some adjustments," Rowson said. "We were working on getting him to focus on controlling his head and driving the ball to the middle of the field. When he got comfortable doing it, it took a few days but he started to come along and cut down on strikeouts and hit some balls hard. He started to get consistent, and then they started pitching him differently and he was a little inconsistent.
"It was a stretch where I saw some adjustments and I actually talked to Dale during that time and told him I thought [Jackson] was making some strides and he looked good at that time."
Now the question is: Would Jackson benefit working with Rowson and Sveum at the big league level -- and facing big league pitching?
"That's the million dollar question -- when do you start the development here?" Sveum said. "There are a certain few people who walk into the big leagues and have success. It usually comes down to who can make the adjustments and who can handle the third deck of the stadium. You have to find out sometime."
When is still to be determined.
"You never know," Rowson said. "[Jackson's] talent speaks for itself and even though you look at the punchouts, he drives it for extra base hits. I know he was really good in spring and probably pressed a little early [in the season], I would say, just in talking to him. I know he pressed a little, he didn't get off to a great start, and was probably pressing and trying to do too much and never really recovered. We'll have to wait and see."