Immediately following the GCL season, one of the talks of the league was how good Kolby Allard, the Braves first pick in the 2015 draft, looked in limited action. It was well known that he had a back issue that caused him to miss a good portion of his senior season, but the understanding, amongst many followers of the Braves' minor leaguers, that the injury wasn't a concern going forward.
However, rumors began to surface here and there, in particular from Kiley McDaniel while he was at Fangraphs, that Kolby's back issue had flared up again and that contributed to his limited action in the GCL. Well given that Kiley is now a member of the Braves' front office, it seems like the news today may have been of no surprise to those "in the know"
Its hard to make sense of the information available about the procedure, but the majority of the sources seem to indicate that it was a minor procedure that should not affect his availability for Spring Training or the season itself. There are some reports that he had two vertebrae fused, but the Braves very quickly corrected that and declared that false. However, it is a situation worth monitoring and we will report new credible information as it becomes available.