MLB.com's No. 63 overall prospect has been experiencing discomfort in his right (throwing) elbow since Christmas, according to D-backs general manager Kevin Towers, who said the ulnar collateral strain is not expected to require surgery.
"He's probably two weeks away from starting a throwing program and probably starting to hit off a tee," Towers told MLB.com.
"If there's a strain, it's the right area to have a strain. He doesn't need Tommy John, doesn't need to be surgically repaired. Nothing we're overly concerned about, but just with a new player here and with no history with the player, just trying to err on the side of being cautious, if anything."
Acquired from the Reds as part of a three-team trade in December, the left-handed hitter batted .265 with seven homers and a career-high 54 RBIs in 129 games between Double-A Pensacola and Triple-A Louisville last season.
The Netherlands native made his Major League debut on Sept. 5 and hit .300 with two RBIs in eight games for Cincinnati.
Gregorius, the D-backs' No. 3 prospect, has not swung a bat or thrown a ball for a month, but Towers said there's still a chance the 22-year-old will get some Cactus League at-bats before the team breaks camp.
Gregorius will start the season in the Minor Leagues, regardless of how many Spring Training games in which he appears, although Towers said he does not expect the injury to impact his long-term future.
"We think with the glove and stuff, he's ready right now," Towers added. "But it's not going to hurt him if he gets more ABs in the Minor Leagues before he's up here. We don't view him as a bench player, so when he comes up here we want him to play. And we've got a couple of good veterans for this year that can handle the position."