"Obviously we're well aware of what he's dealing with and we support him," said Red Sox manager John Farrell. "He's a talented young guy and we'll provide every available resource to him to get back to being a productive pitcher and a guy that we'd hope to factor in as we go forward."
The Red Sox selected Johnson with the 31st overall pick in the 2012 Draft. He made one start for Boston last July at Houston and probably would have made more if not for elbow soreness ending his season prematurely.
In seven starts for Pawtucket this season, the 25-year-old Johnson is 2-3 with a 4.64 ERA.
Ian Browne has covered the Red Sox for MLB.com since 2002. Follow him on Twitter @IanMBrowne and Facebook. This story was not subject to the approval of Major League Baseball or its clubs.