Heyward also has recorded at least two hits in 12 of his last 20 games, a span in which he's batted .411.
"It's the second half of the season. I've had plenty of AB's now to feel out where I need to be," Heyward said on Tuesday. "I did pay attention to the games and tried to stay focused."
Heyward said he's continued to undergo treatment, but he no longer feels any pain or stiffness in his back. He unsuccessfully lobbied manager Fredi Gonzalez to put him in the lineup the series for last week's finale against the Dodgers.
"It was frustrating in L.A. trying to get back on the field," Heyward said. "I tried to convince [Gonzalez] that I wanted to play the last day there, and he said, 'No, you need to rest.'"