Fister has been icing the elbow and going through other regular usual anti-inflammatory treatments, according to manager Matt Williams, who reiterated that an MRI showed there are "no structural issues."
Fister is shut down for now, but once the inflammation is gone, Williams said the righty will throw on the side. If that goes well, the team will decide if he needs to throw a bullpen session or if they can schedule him for game action.
"Certainly you want to progress him through Spring Training and make sure he's ready to pitch," Williams said. "But if stuff like this happens, there's nothing you can do except get it healthy first, then proceed. That's our plan of action. Time frame, we just don't know."
Andrew Simon is a reporter for MLB.com. Follow him on Twitter @AndrewSimonMLB. This story was not subject to the approval of Major League Baseball or its clubs.