Scherzer (forearm/thumb/ankle) threw a 20-pitch bullpen session Monday, Jorge Castillo of ESPN.com reports.
Scherzer is working his way back from ankle, forearm and thumb issues and required cortisone injections to combat each of the latter two injuries. He will continue ramping up his throwing as his body allows, but a timeline for his return won't be available until he gets farther along. Scherzer has been sidelined since late April.