AP Sports Preview Diamondbacks at Cardinals ST. LOUIS (Interstat) — The Arizona Diamondbacks and St. Louis Cardinals, separated by one game in the standings, open a pivotal four-game series Thursday at 7:15 p.m. CDT at Busch Stadium III. Arizona (53-49) holds a slim half-game lead over St. Louis (52-49) in the National League wild-card race. The forecast calls for 82-degree temperatures and cloudy skies. Right-hander Michael McGreevy (4-7, 4.91 ERA) will start for the Diamondbacks. He has lost four of his past five decisions. The Cardinals will counter with right-hander Hunter Dobbins (2-0, 2.45 ERA). Dobbins earned a win in his last start Wednesday at the Los Angeles Angels, pitching six scoreless innings in a 1-0 victory. He allowed six hits and struck out five. Players to Watch Arizona right-hander Merrill Kelly has been strong in recent outings. In his last start Wednesday against Oakland, Kelly allowed two earned runs on five hits over five innings in a 15-5 win. Over his past four starts, he is 2-1 with a 2.35 ERA. For the Cardinals, Dobbins has allowed one run over his past 11 innings. The rookie right-hander has struck out nine batters in two major league appearances. Series History The teams split a three-game series last weekend in Arizona. The Diamondbacks won 8-7 in 10 innings Sunday, and 5-3 on Saturday. The Cardinals took the opener 5-4 on Friday. Arizona has won four of the past six meetings overall. Recent Results The Diamondbacks defeated Oakland 15-5 on Wednesday after splitting a doubleheader Tuesday. Arizona took three of four from the Athletics. The Cardinals won 1-0 at the Angels on Wednesday, taking two of three in Anaheim. Projection Interstat’s game simulator projects a 6-4 Arizona victory. St. Louis is a -1.5 run favorite. The over/under is 8.5 runs. Upcoming The Diamondbacks travel to Washington for a three-game series beginning Friday. The Cardinals host Cincinnati for a three-game set starting Friday.