That could be difficult this time around with the Padres improving outside San Diego.Arizona continues its push for the NL West lead in Friday night's series opener.After getting swept in their last series against San Diego (46-57) from June 14-16, the Diamondbacks (53-49) have dropped 15 of 21 in this divisional matchup, including six of nine in 2013. Arizona, though, won its second straight home series against the Padres from May 24-26, taking two of three in San Diego's lone visit this season.The Diamondbacks, one-half game behind the West-leading Los Angeles Dodgers, continue their seven-game homestand after splitting four with the Chicago Cubs. Aaron Hill, out of the lineup the previous two games, went 2 for 4 with a homer and two RBIs in Thursday's 3-1 victory.The Diamondbacks had dropped five of seven.The Padres, meanwhile, are trying to build off their first road series win since May 14-15 against Baltimore. San Diego took three of four from Milwaukee after totaling 16 hits in Thursday's 10-8 victory.The club is batting .300 and averaging 5.0 runs in the first seven games of its trip, which started with San Diego losing its 10th straight on the road."I think one of the biggest things for us is our ability to put pressure on pitchers, even if it's not with hits … just making them work hard," Yonder Alonso told the Padres' official website. "We've got the ability to really grind out some at-bats, and when you do that, good things happen."Scheduled starter Randall Delgado (2-3, 3.43 ERA) has been making good things happen for the Diamondbacks.The right-hander hasn't allowed more than three earned runs in any of his seven starts. Delgado prevented the Diamondbacks from dropping a fourth straight in his last outing, working around a season-high four walks and throwing 5 2/3 shutout innings in Sunday's 3-1 win at San Francisco."Delgado was a stopper today," Cody Ross told the Diamondbacks' official website. "He threw outstanding."Delgado, though, could be out of the rotation after this start with Brandon McCarthy (right should inflammation) nearing a return.Wil Nieves could be behind the plate again for Arizona with Miguel Montero missing the last three games with inflammation in his back. Montero is day-to-day.Padres catcher Nick Hundley, 6 for 17 with two homers on the trip, should be back in the lineup after getting Thursday off.Eric Stults (8-8, 3.45) gets the ball for San Diego in the opener. The left-hander was denied a career-best third consecutive winning start Sunday, but he delivered another quality performance, throwing six innings of three-run ball in a 3-2 loss to St. Louis."He ran into some longer innings but he did his thing," manager Bud Black said.Stults will make his third start against the Diamondbacks this season. He allowed four runs in 6 1/3 innings of a 5-2 loss at Arizona on May 24, then threw a two-hitter in a 2-1 home win June 14.Martin Prado, 6 for 17 off Stults, should be available after he was shaken up on a headfirst slide Thursday. Prado is batting .353 with five doubles against Padres pitching this season.San Diego's Everth Cabrera is 14 for 35 with two homers and seven RBIs in the season series. No Padres player has faced Delgado.