Gallen (shoulder) will throw a live batting-practice session Monday, Nick Piecoro of the Arizona Republic reports.
Gallen continues to make progress from offseason shoulder issues, but the right-hander is unlikely to be part of the rotation's first turn to start the season. It's uncertain when Gallen will make his first Cactus League start, and he may not build up enough pitches to be ready the first week of the season. The Diamondbacks start integrating their rotation locks beginning Tuesday when Madison Bumgarner pitches.