With Bronson Arroyo's back acting up, Schultz remains among the candidates to replace him in the rotation if Arroyo is not ready for Opening Day.
Meanwhile, Eric Stults, who is expected to be the Padres No. 5 starter, rebounded after a pair of poor outings to allow a pair of runs on five hits over 3 1/3 innings. Stults came into the game with a 27.00 ERA in his first two starts.
"Stultsy's stuff played to his norm," Padres manager Bud Black said. "He's still not as in shape as we'll see him in the season. But I thought overall he got [inside] on some guys' hands and broke some bats and got to his pitch count."
The Padres got on the board first when D-backs right fielder Gerardo Parra dropped leadoff hitter Alexi Amarista's fly ball for a two-base error.
One out later Jedd Gyorko drove home Amarista with a single to center.
After stranding a pair of runners in the first, the D-backs managed to break through in the second thanks to a two-out rally.
Tuffy Gosewisch singled to start it off and Schultz helped himself with a bloop single to right.
A.J. Pollock then drove them both home with a triple off the wall in right-center as Arizona took a 2-1 lead.
The Padres tied the game in the eighth inning when Alex Dickerson drove in Jace Peterson on an RBI double off Brad Ziegler.
Up Next: The Padres return to Salt River Fields at 1:05 p.m. PT on Monday, this time to face the Rockies. The game can be heard on an exclusive webcast on Padres.com. Andrew Cashner will make his third start of the Cactus League season. Cashner, who figures to be the team's Opening Day starter on March 30, hasn't allowed a hit in five innings thus far. He'll likely throw in upwards of 60 pitches against the Rockies, as he continues to get stretched out.
Steve Gilbert is a reporter for MLB.com. Read his blog, Inside the D-backs, and follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.