The announcement came after Atlanta's 6-5 victory Sunday to fend off elimination for at least another day. The Dodgers hold a 2-1 lead in the best-of-five series.
"We're going to go with Folty," Snitker said. "He went two innings, 50 pitches [in Game 1]. He's good. That's just a workout. Quite honestly, I'd rather start him than have him coming in behind somebody."
Foltynewicz started Game 1 of the series in Los Angeles but struggled with his command and departed after just two innings. Foltynewicz allowed four runs, three walks and two homers in the outing, throwing 50 pitches.
However, Foltynewicz was Atlanta's top starter during the regular season, his best as a major leaguer. He went 13-10 with a 2.85 ERA and 202 strikeouts -- all career-best marks. He also pitched in his first All-Star Game.
"He's raring to go and itching to get the ball, and it's still elimination," Snitker said. "So we're going to try and go with the best we got."
Dodgers manager Dave Roberts did not announce his Game 4 starter during his postgame news conference, though lefty Rich Hill is expected to get the nod.
If the Braves win Monday at SunTrust Park, Game 5 will be played in Los Angeles on Wednesday. The winner of the series will advance to the NL Championship Series to face the Milwaukee Brewers, who completed a three-game sweep of the Colorado Rockies on Sunday.