you mean the ordinary issues that happen when a bullpen is assembled using duct tape and bailing wire? Or hell, when an ordinary bullpen is used, period, and attrition happens? A few trips back and forth to the DL is pretty normal procedure for a reliever, it's more normal for it to happen at least once than for it not to.
Plan A went out the window before Opening Day even started, with the injury to Carson Smith. If you want the reason why a lot of our other bullpen stalwarts got used a lot more than they should have, that's a good place to start.