PITTSBURGH (Interstat) — The Arizona Diamondbacks and Pittsburgh Pirates open a pivotal three-game series at PNC Park on Monday at 7:05 p.m. EDT, with both clubs jockeying for National League wild-card positioning. Forecasts call for 79 degrees and rain. Arizona (55-51) enters as a minus-1.5 favorite, according to Interstat’s game simulator, which projects a 7-5 victory for the Diamondbacks. The over/under is 8.5 runs. The Diamondbacks dropped their series finale in Washington on Sunday, falling 10-7 to the Nationals. Catcher Gabriel Moreno continued his torrid stretch, going 2 for 3 with two RBIs. Over his past six games, Moreno is batting .375 (9 for 24) with six RBIs, including a 3-for-4, two-RBI performance July 23 at St. Louis. The Pirates (54-52) rallied for an 8-7 win over the Chicago Cubs on Sunday at PNC Park. First baseman Ryan O’Hearn drove in four runs on a solo home run and added three walks, finishing 1 for 2. O’Hearn has been productive at home this season but is just 2 for 18 over his past six games. These teams met May 5-7 in Phoenix, with the Pirates winning the final two games of the three-game set. Pittsburgh took the series opener 4-2 on May 7 and a 1-0 pitchers’ duel May 6 after Arizona won 9-0 in the first game. Arizona is 5-5 in its past 10 games, while Pittsburgh is 6-4 over the same stretch. Probable starters for Monday’s game were not announced. Players to watch: — Gabriel Moreno, C, Diamondbacks: The 26-year-old Venezuelan has hit safely in seven of his past eight starts with at least one RBI in five of those contests. — Ryan O’Hearn, 1B, Pirates: He delivered the decisive blow Sunday with his 11th home run of the season and has 48 RBIs. The series continues Tuesday and Wednesday before both teams hit the road for divisional matchups. Arizona travels to Cleveland for a three-game set starting July 31, while Pittsburgh opens a four-game series at Cincinnati on July 30.