"He may be the hardest-working guy I've been around," manager Fredi Gonzalez said. "It's hard to tinker with a swing, or make adjustments, and put him in the game and try to produce. But for me, great attitude, keeps working hard. You pull for those guys."
On Monday, Upton continued to work on the problem with hitting coach Greg Walker and assistant hitting coach Scott Fletcher. The trio were pouring over video in hopes of finding a solution.
What Upton and the Braves staff have been working on mainly is getting his foot down earlier to attack the fastball. The outfielder has found himself late on fastballs recently.
"That was the big thing," Gonzalez said. "You get your foot down on time, get ready to hit, get ready to attack, clears up a lot of the other stuff."
The former Rays second-round Draft pick in 2002 has never been known for his batting average, sporting a career .251 mark, but even his on-base percentage this season sits nearly 100 points below his career norms.
The solution, however, is not easy to implement once the season is underway.
"It's tough during the season to make a lot of big changes," Gonzalez said. "But the adjustments they're talking about aren't big swing changes, they're not big mechanical changes, it's just getting your foot down on time.
"It's hard to in the middle of the Major League season and start trying to make swing adjustments. But I think you can make small adjustments."
Evan Peaslee is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.