Gallen (elbow) will throw a 45-pitch simulated game Saturday, Jody Jackson of Bally Sports Arizona reports.
He completed a 32-pitch simulated game Monday and will advance to three innings/45 pitches this weekend. Gallen will presumably advance to a rehab assignment if he continues progressing without setbacks and is tracking toward a late-June return to the big-league rotation. However, given the nature of his injury, there is some risk of a setback every time he takes the mound.