ST. LOUIS – While the Braves prepared for a series opener Thursday at St. Louis, teammate Jason Heyward was back in Atlanta, having metal plates surgically attached to his broken jaw to mend two fractures from being hit in the face by a fastball Wednesday at New York.

Their hot-hitting leadoff man and gifted right fielder was out of sight, but Heyward was not out of the minds of the Braves, who will probably have to make do without him for at least the rest of the regular season. The Braves haven’t given a timetable for his return, but it typically takes four to six weeks to recover from a broken jaw.

“I think it changes the team,” said rookie outfielder/catcher Evan Gattis, who could get most of the playing time in left field while Heyward is out, with Justin Upton moved from left field to right. “We’ll just see what happens, but I think it’s a big piece we’re missing. Especially him leading off. It’s been really good; we’ve been playing really good ball. Somebody said dynamic; we’ve been much more dynamic with him leading off.”

The Braves’ inconsistent offense got steadier and more productive after Heyward was moved to the leadoff spot July 27, the second game of a 14-game winning streak. He batted leadoff in all 21 of the 23 games he had started since then, and for the season he had a .341 average with six doubles, five homers and a .414 on-base percentage and .580 slugging percentage in 88 at-bats as a leadoff hitter.

That surge by Heyward came to an abrupt halt Wednesday when Mets left-hander Jonathon Niese threw a 90-mph fastball that struck Heyward in the right side of his face, just below the ear flap.

“You’re never trying to hit guys in the face,” veteran Braves backup catcher Gerald Laird said.”It’s just like a freakish thing. It’s not a good feeling when you get up in the head area. You’re fooling with guys’ careers up there, and you never want to see anybody get hurt and not be able to play the game they love to play. They’re trying to provide for themselves and their family.

“(Niese) looked concerned. I mean, not to say he did it on purpose – I don’t think he did – but for a guy who has as good a control as he does, it just brings a little bit of doubt in your mind. Because he was pretty much cruising that whole game, spotting his pitches, then all of a sudden one gets away. Who knows if it was a purpose pitch to kind of back him off and it got away. But I don’t think any time a guy tries to throw at someone that he tries to hit him in the face. I don’t think he tried to do that.”

While the team flew from New York to St. Louis after Wednesday’s game, Heyward flew home Wednesday night and was operated on Thursday by Dr. Glenn Maron. Heyward had plates attached to fractures on the right side of his jaw and his chin.

“They did not wire it shut, which is a good thing, because he can get food in him,” Braves manager Fredi Gonzalez said. “He does have a couple of rubber bands, but that’s just a reminder to not open your mouth too wide. He sounds good on the text. He said he’s going to see us when we get back home. He wants to be with the club.”

“It’s a tough blow,” Laird said. “The way he was at the top of our lineup, getting on base, driving in runs, got some big hits in some tight games to win games for us. Is he replaceable? No. He’s an unreplaceable player. A guy of is caliber, the defense he plays out there, the offense he brings now that he had kind of figured it out. Really tough blow.

“But I talked to the guys and told guys, it’s one of those things where we have to gather ourselves and play. He ain’t going to be here. Yeah, it’s a big blow. But I remember in 2011 when I was here (with the Cardinals) and we lost (pitcher Adam) Wainwright before the season even started. We lose our No. 1 starter and we go to the World Series and win it.”

Gonzalez said he hadn’t been told a time frame for Heyward’s return. He noted that six weeks would be when the postseason begins.

“We just hope he gets a speedy recovery,” Gonzalez said. “The good thing I know is, by not being wired shut, he can keep his weight on.”

When Heyward is ready to return to baseball activities, he’ll play in instructional league games in Florida. Braves minor league affiliates will have concluded their seasons, so a rehab assignment won’t be possible.

Gonzalez plans to use Jordan Schafer in the leadoff spot whenever Schafer is in the lineup, likely against most or all right-handers. Schafer has been platooning recently with struggling veteran center fielder B.J. Upton, but Schafer can play any outfield position.

Switch-hitting rookie Joey Terdoslavich is also expected to get some starts in left field and perhaps in right.

The Braves hope that others can help pick up the slack caused by Heyward’s absence. Second baseman Dan Uggla, who’s been recovering from Lasik eye surgery, is scheduled to play a rehab game or two next week and be activated Wednesday, the first day he’s eligible.

Heyward struggled in April and May, both before and after an appendectomy, but hit .301 with a .377 OBP, .504 slugging and 27 extra-base hits (11 homers) in his past 64 games since June 2.

“It’s tough,” B.J. Upton said. “He’s been playing well. You never want anything like that to happen. We got the news after the plane flight yesterday, and you could just see the look on the guys’ faces when we found out. Like I said, that’s a big loss. But at the same time, we’ve got to find a way and just pick up where he left off. Hopefully we get him back sooner than later. Hopefully we’ll get him back for the right time.”

“The way he had been playing was definitely the way he wanted to play. He’s been a big part of why we are where we are. You hate to see anything like that. It’s a tough loss, it’s a big one. But we’ve got the personnel to fill in and kind of pick up the slack.”