Johnson will pitch out of the bullpen for the remainder of the season, Pete Abraham of The Boston Globe reports.
Johnson will shift back to a long-relief role for the stretch run with David Price (wrist) slated to come off the injured list to start Sunday against the Angels. The southpaw has made five appearances since returning from the IL at the beginning of August, posting a 7.20 ERA, 2.13 WHIP and 9:9 K:BB across 15 innings.