He said he threw 40-45 pitches in his previous bullpen session, and he'll increase the workload by 20 pitches Monday.
Harrison underwent a second operation in May to address a herniated disk in his lower back. Harrison said earlier this month he looked to return at the end of August. It appears he is ahead of his projected target.
Master Tesfatsion is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.