Pitchers Josh Collmenter and Takashi Saito and infielder Willie Bloomquist were activated from the disabled list and the team added infielder Cody Ransom to the roster after claiming him off waivers from the Brewers on Friday.
Only two players, catcher Konrad Schmidt and outfielder Tyler Graham, were called up from Triple-A Reno, because Reno has qualified for the playoffs so the D-backs do not want to disrupt its roster too much at this point.
When Reno's season does end, the D-backs plan to promote others to a roster that now may grow from 25 to 40.
For now, though, they felt like they could not wait to add a third catcher in Schmidt.
As for Graham, he was a surprise promotion given his .115 average in 26 games for Reno. However, Graham gives the D-backs speed off the bench and a defensive replacement in the outfield, while not taking away a starting outfielder for Reno.
"He's kind of a speed guy," D-backs manager Kirk Gibson said. "Another outfielder, runs pretty good. We've been playing with four bench players which makes it tough to burn anybody."