"He looked good and felt fine, so that's a great sign," Black said. "There's been a couple setbacks along the way and that happens, and today was a good sign. It's just another little step, there's still a lot of ground to cover."
This small milestone comes after Luebke experienced a pair of hitches in his recovery. Early in the season, he had his first attempt at a throwing program shut down for about six weeks after he experienced soreness.
Luebke got the point of being able to play catch off the mound in May, but felt some discomfort in his left elbow after a throwing session and was shut down again.
Lubeke will take a couple days off and if he's not feeling any discomfort, will likely throw another bullpen on Thursday or Friday. As he gets closer to participating in full baseball activities, he could go with the Arizona summer league team to participate in their drills and complete his bullpens there.
If he continues to progress along this schedule, Luebke could participate in the instructional league in Arizona beginning in September.
"You hear the 12-to-18 month number," Black said. "Not all of them follow the same path. ... Cory is making progress now, so lets keep our fingers crossed that it continues."
Jamal Collier is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.