"It wasn't feeling too great in Spring Training," Luebke said of his level of confidence in his changeup, "but when I injured my oblique, it gave me the chance to work on it during my bullpen sessions."
Luebke, who already had a low-90s fastball he could command as well as a sharp slider, took advantage of his time at San Diego's Spring Training facility in Arizona during the rehabilitation process to refine the changeup.
How comfortable does Luebke feel with the pitch now?
Luebke estimates that he threw it 15 or so times in his victory over the Dodgers last week -- which so happened to be the left-hander's first Major League victory.
Luebke, who will make his third Major League start Monday in Denver against the Rockies, has gotten to the point where throwing that pitch no longer represents a leap of faith for him.
"I give a lot of credit to [catcher Yorvit Torrealba] for making me throw it, especially in fastball counts," Luebke said.
San Diego pitcher coach Darren Balsley, who impressed upon Luebke the need for a third pitch back in Spring Training, has been impressed by what he's seen.
"The changeup isn't quite a third pitch for him yet, but it's a legit pitch, and for me, it has been a pleasant surprise," Balsley said. "You've got to give him a lot of credit."
Luebke suffered the oblique injury right at the end of Spring Training, while he took -- if you can believe this -- batting practice with manager Bud Black throwing. He didn't pitch in his first Minor League game until May 25 with Double-A San Antonio.
Luebke went 5-1 with a 2.40 ERA in 10 games with the Missions before being promoted to Triple-A Portland, where he was 5-0 with a 2.97 ERA in nine starts.