Manager Kirk Gibson said Wheeler earned some starts with good at-bats as a pinch-hitter.
"[Pinch-hitting] really makes you get with it," Gibson said. "It's not like you're getting a consistent three or four at-bats a game. We saw some improvement there."
Gibson also felt Wheeler put in the work in the batting cage and in the infield before games.
With Wheeler starting, Chris Johnson was relegated to pinch-hitting duty for the second straight day. Johnson is hitless in his last 16 at-bats. He started two of the D-backs' past five games after starting in his first 13 as a D-back.
Gibson said before Saturday's game that he was trying to keep players fresh as they started a stretch of five games in four days. Justin Upton also had the day off on Sunday.