"The big thing is that he's getting into a solid setup where he's been able to maintain his back side and create some aggression just with his hands," Barnett said. "He's using his hands so much better right now, it's unbelievable."
Part of the improvement, in Barnett's eyes, stems from a new approach to physical preparation that strength and conditioning coach Dr. Gene Coleman suggested to get Lee into the game a little less cold.
"Trying to improve his first-at-bat productivity, he's been doing a strenuous workout before the game and it's definitely helped," Barnett said.
"It's doing a lot of leg-strengthening stuff and things to maintain his back side so his hands can work the right way."
Heading into the All-Star break, Lee was hitting .268 with a .316 on-base percentage and a .425 slugging percentage. Since the break, it's been considerably improved with a .291 average, a .371 on-base percentage and a .502 slugging percentage.
As the base hits have come, his home run rate has experienced a drastic change too, from one every 48.4 at-bats to one every 19.4. It's part of a progression that Brad Mills explained.
"He's going the other way a lot more," Mills said of Lee, whose single in the fifth inning of Sunday's 3-2 win over the Cubs went the opposite way.
"He'll take his base hits and doubles to right-center and the other way and then all of a sudden when they do make a mistake over the plate, he's able to hurt them."