Gillespie, who is expected to compete with Gerardo Parra for playing time in left field given last week's trade of starter Conor Jackson, joined Arizona for the second time this season; previous to his May 19 demotion, he went 10-for-39 at the plate in 17 big league games.
"With the Conor move, you got two guys that are probably going to play the majority of the time," Gillespie said while sitting down in front of Jackson's old corner clubhouse locker. "Hopefully, Parra and I kind of find our way in there and help this team out."
Gillespie, 26, was batting .289 with five home runs and 29 RBIs in 40 games for Reno. He overcame a flu bug that made him feel "weak for a week" and cost him game action on June 14.
While ensuring Gillespie is 100 percent healthy, Arizona manager A.J. Hinch declined to use the word "platoon" regarding the left-field position. He was much more inclined to complement Parra, who was batting .296 over his past 10 games despite a 2-for-11 slide during the D-backs' weekend series against the Tigers.
"It looks like his rhythm is getting a little better at the plate," Hinch said. "He actually hit the ball as well as anybody in Detroit; he doesn't have a ton to show for it."
Hinch added that the move gives him two players -- Parra and Gillespie -- who can play all three outfield positions and, therefore, give a breather to starters Chris Young in center field and Justin Upton in right. (Utility man Rusty Ryal remains a viable option as a left fielder.)
Roberts, a left fielder/second baseman who was optioned to Triple-A to pave the way for Gillespie's return, collected three hits in 17 at-bats in his 12-game stint with the D-backs. But two of those knocks proved crucial to victory: He struck a walk-off single on June 4 and, in another pinch-hitting appearance the next night, a two-run double that pushed Arizona to consecutive one-run wins over the Colorado Rockies.
Andrew Pentis is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.