Schumaker, who was injured during a March 21 diving catch attempt, throws right-handed but had discomfort in his left shoulder in earlier attempts to throw. That is no longer an issue.
"That left arm has to come up. It has to establish height and closure to stabilize and really allow him to extend and throw through the ball," Price said. "It's a very important piece of the throwing mechanics, even though he's a right-handed thrower. That used to hinder him."
Another player on the DL, lefty reliever Sean Marshall, is also advancing his efforts to return. Marshall, who missed all of Spring Training because of a sore left shoulder, threw one inning and 19 pitches on Saturday at extended spring in Arizona.
Marshall is slated to begin a rehab assignment on Tuesday at Triple-A Louisville and pitch an inning in back-to-back games. There is a chance he could be activated before the end of the week.
"We certainly don't want to put the cart in front of the horse here. We want him to get through these outings," Price said. "Going back to back for the first time is a huge step in the right direction."