ST. LOUIS (Interstat) — The Atlanta Braves look to avoid a three-game sweep Sunday afternoon at Busch Stadium III, where they face the St. Louis Cardinals in a matchup of National League contenders vying for positioning before the All-Star break. Atlanta (54-39) holds the best record in the NL East but has dropped the first two games of this series by a combined 6-1 score. The Cardinals (49-44), winners of four of the last five meetings between the clubs, have tightened their grip on an NL wild-card spot. The forecast calls for 80-degree temperatures with rain, which could affect strategy for both bullpens. For Atlanta, left-hander Chris Sale looms as a key figure. Sale last faced the Cardinals on Friday, allowing two hits and no earned runs over three innings with five strikeouts in a 2-1 loss. In his five-inning outing July 4 against the New York Mets, he surrendered three runs on seven hits but earned the win. Sale also posted a 10-strikeout performance June 28 at San Francisco, taking a hard-luck loss despite allowing one earned run over six innings. For St. Louis, right-hander Kyle Leahy has been a bright spot. Leahy earned the win Friday after tossing three scoreless innings of relief, giving up one hit and striking out two. He followed that with a five-inning shutout effort July 4 at Chicago, scattering three hits with six strikeouts. Over his last four appearances, Leahy has not allowed an earned run. St. Louis enters as a -1.5-run favorite, according to betting lines, with an over/under of 8.5 runs. Interstat’s game simulator projects a 5-4 victory for Atlanta. The series has been dominated by pitching. In Friday’s 2-1 Cardinals win, St. Louis relievers Riley O’Brien (one inning, two strikeouts) and Justin Bruihl (1 2/3 innings, one strikeout) combined to hold Atlanta scoreless after Leahy’s exit. The Braves’ Victor Mederos (two innings, three strikeouts) and Tyler Kinley (one inning, one strikeout) also turned in scoreless outings in the loss. Saturday’s 4-0 Cardinals victory extended St. Louis’s home winning streak against Atlanta to two games. The Braves, who went 4-3 on a homestand against the New York Mets and Pittsburgh, will open a six-game homestand Friday against Texas. The Cardinals, coming off a 4-3 loss to Milwaukee on Thursday, begin a nine-game road trip Friday at Arizona.