According to manager Matt Williams, after three straight days of playing catch, following a day of rest for his inflamed elbow, Fister felt tightness in his arm. Fister believes the tightness is a combination of increased activity and the elbow discomfort. The right-hander went on to say that he does not feel like this was a setback, but a result of his current throwing program. He is still slated to throw a bullpen session on Friday, but it will depend on how he feels.
Source: Washington Post