Manager Fredi Gonzalez said it's just a matter of running into a team that's on a roll.
"It's throughout the lineup, and I don't think the effect of one guy gets to the bottom of the lineup," Gonzalez said after the St. Louis Cardinals beat them for the third straight time behind strong pitching from rookie Shelby Miller in a 6-2 victory on Saturday night.
"We hit a lot of balls hard," No. 5 hitter Brian McCann said. "We just didn't get anything going and they made good plays when they had to."
Heyward had been one of the Braves' hottest hitters before getting sidelined by a broken right jaw after being hit by a pitch. He underwent surgery Thursday and the team has not said how long he'll be out, but he could miss the rest of the regular season.
Miller worked seven innings of three-hit ball and Matt Carpenter and Carlos Beltran homered for the Cardinals.
Freddie Freeman homered for the NL East-leading Braves, who totaled five runs while dropping three in a row for the first time since July 3-5. Julio Teheran (10-7) allowed a season-worst five walks and was charged with four runs.
"We've got to start swinging the bats, we've got to keep the line moving offensively," Gonzalez said. "I think our pitching will be fine.
"I really like the three guys they threw at us and hopefully we get a chance to come back and play good baseball like we normally play."
Miller (12-8) worked more than six innings for the first time in 13 starts since June 1. He struck out six without walking a batter while pitching with no more than a one-run cushion against a fellow 22-year-old right-hander. Center fielder Jon Jay made a leaping catch at the wall to rob McCann of at least extra bases in the seventh.
"I didn't think he was going to catch it, but I didn't know if I got enough to get it out," McCann said. "Obviously, I didn't."
The Cardinals, who began the night a game back in the NL Central, go for a four-game sweep Sunday with Lance Lynn (13-7) opposing Mike Minor (12-5).
St. Louis totaled three runs while getting swept in a three-game series in Atlanta in late July and Gonzalez said the Cardinals, who have won seven of eight overall, are playing as well now as the Braves were then.
Pinch-hitter Shane Robinson and Carpenter opened a three-run seventh with singles to chase Teheran and the Cardinals broke it open against reliever Dave Carpenter with a two-run double by Matt Holliday and an RBI single by Yadier Molina for a 5-1 lead.
Teheran struck out eight but hung sliders on both home runs.
"I knew it from the first inning, when I was warming up, that it was going to be a hard day for me," Teheran said. "That was the two mistakes I made. I didn't try to think about it, just tried to stay in the game."
The Braves had three of their seven hits in the ninth, including pinch-hitter Gerald Laird's RBI double off Seth Maness before Edward Mujica struck out Elliott Johnson with two on for his 34th save in 36 chances.
The first three hits of the game were home runs. Miller struck out the first two batters on seven pitches and the Braves' first contact came when Freeman hammered a 1-2 pitch for his 16th homer.
Carpenter answered with his second career leadoff homer and 10th overall, also on a 1-2 count, in the bottom of the first. Beltran's team-leading 23rd put the Cardinals ahead 2-1 in the third and he finished with three hits, two RBIs and his second base-running gaffe of the series.
Beltran settled for a single in the fifth after standing at the plate for several seconds and belatedly jogging to first on a liner down the third base line that caromed off the jut in the stands in shallow left. Two days earlier he missed third base and had to double back before scoring.