Gallegos (groin) is now dealing with lower-back tightness, Brendan Kuty of NJ.com reports.
Gallegos initially landed on the minor-league disabled list with a groin injury. While he's reportedly over the groin issue that forced him to open the season on the shelf, his 2018 debut is now being delayed by a back ailment. It's unclear when he'll be able to return at this point.