Right-hander Zack Godley (7-5, 4.77 ERA) is scheduled to face Pittsburgh righty Ivan Nova (4-5, 4.42) in the opener and, in fact, the Diamondbacks (40-33) have starters penciled in all four games against the Pirates (36-37).
But starters Shelby Miller (Tommy John surgery) and Robbie Ray (strained right oblique) appear close to returning, particularly Miller.
"He's getting close," Diamondbacks manager Torey Lovullo said of Miller. "With these outings and the feedback he's giving us, he's telling us that he's getting closer every day."
One possibility is that Miller will replace Matt Koch, who allowed five runs in 5 2/3 innings Wednesday in a 5-4 loss against the Angels.
"Yet to be determined," Lovullo said. "We're going to huddle up and have some conversations ... and figure out what the next course of action."
In the meantime, Godley is 2-0 with a 2.92 ERA over his past two starts. That includes a 7-3 win Friday against the New York Mets when he gave up two runs in 6 2/3 innings.
"I had to fight through myself pretty much for the first three innings and then after that kind of settled in a little bit and got some quick outs and was able to go deep into the game," Godley said. "I was just kind of fighting myself body-wise, just kind of not finishing some of my pitches and leaving some up and in on righties and up and away on lefties."
Getting through that impressed Lovullo.
"He's battling himself," Lovullo said of Godley's early innings in that game. "He can't duplicate pitches, and he just made some key pitches at the right time. ... So, when you see things like that when a guy doesn't have his best stuff, that's what sticks out for me. Pretty impressive."
Godley is 0-0 with a 4.50 ERA in two appearances, one start, against Pittsburgh.
The Diamondbacks, who were off Wednesday, have won eight of their past 12 games. That includes taking two of three last week when the Pirates visited Chase Field.
Pittsburgh last lost two home games in a row against Arizona but had won six in a row before that.
The Pirates have won four of six after getting an impromptu day off Wednesday -- their game against Milwaukee was postponed after a rain delay of more than two hours.
Nova, like Godley, is coming off two good starts, going 2-0 with a 1.54 ERA since he came off the disabled list (sprained finger).
On Saturday, he struggled with his curveball but it didn't stop him from allowing just one run and five hits in six innings in a 6-2 win over Cincinnati.
"Even though I walked a couple guys, the fastball command is better than what it was before I hit the DL," Nova said. "I think I've been able to control it a bit better. I think that's been the key."
Nova is 1-1 with a 4.00 ERA in three career starts against the Diamondbacks.
Pittsburgh will be without starting left fielder Corey Dickerson for at least the start of the series. He is on family leave.