Hefner had Tommy John surgery October, 2013.
In his rehab assignment with Single-A St. Lucie, Hefner had a 9.00 ERA in eight innings.
This time of year, it's always possible this is simply a way to make room on the roster for someone else, such as RHP Tim Peterson, who was activated from the DL at the exact same time. Or, it could be an actual injury...
In either case, pain in the forearm is often affiliated with the elbow. Of course, they could have nothing to do with one another, this could simply be fatigue, as B/R's Will Carroll told me, but it's close enough to create concern. What's more, I hope this is a lesson to Matt Harvey, that anything can happen and, while I'm sure he's feeling confident, there is still a long road between here and Opening Day.