"There's just a little bit of irritation up in the upper hamstring," D-backs manager Chip Hale said. "With the higher injury and then the other one still not 100 percent, let's give him the 15 days to get 100 percent."
Freeman, 28, made his Major League debut and went 0-for-3 with three strikeouts and a walk in Sunday's 6-5 win over the Dodgers. He started in right field and batted sixth.
Freeman hit .317 (108-for-341) with 17 doubles, six triples, one homer, 24 RBIs, 38 walks, 11 stolen bases and a .798 OPS in 88 games at Reno.
He has spent the last three seasons at Reno and in that span hit .315 (301-for-957) with 51 doubles, 18 triples, five homers, 90 RBIs, 93 walks and 27 stolen bases in 272 games.
Freeman has spent parts of seven seasons in the D-backs' system since being selected in the 11th round of the 2010 Draft out of Clemson University.
"It's a humbling feeling," Freeman said. "There are a lot of players that I've played against, played with, that are plenty talented to be here, just never got the opportunity, so I'm very grateful."
Freeman was told by Reno manager Phil Nevin that he would be coming to the D-backs on Saturday while hitting in the batting cage. Freeman flew to Phoenix with his wife, Caroline, after receiving the news. Caroline, his parents and a friend were in attendance for Sunday's game.
Hale said Freeman was promoted largely because of the versatility he can bring to the team with a handful of key position players currently on the DL. He has played first base, second base, and all three outfield positions in Triple-A this season.
"Whatever is needed of me, come off the bench, get a hit late in the game, steal a base, play defense all over the field, I think I can help the team win in a lot of ways, make the guys around me better," Freeman said. "My numbers aren't always sexy, but I think I make other guys' numbers sexier just by the way I play. I'm excited to be here, bring a lot of energy, and ready to get going."