Marquez (forearm) has progressed to throwing off a mound, per MLB.com.
Marquez landed on the 15-day injured list May 3 due to right forearm nerve irritation. He resumed throwing in mid-May and has since been able to return to mound work. If he continues to progress without any setbacks, Marquez could be back with San Diego sometime in June, though he'll likely need a minor-league rehab stint first.