"My arm felt good, so that's definitely good, especially being the first time going full bore with the heater and the first time throwing a hard curveball and changeups," Billingsley said. "I was a little rusty, but I was very pleased with the curveball. The timing was a little off, but I threw some good pitches, and overall, I'm pretty pleased with it."
Billingsley had Tommy John surgery on April 25, 2013. He has been throwing since January.
"Now I can start developing a starter's routine, and I'm pretty happy about that," he said. "I can prepare to start pitching in a game. It was the first time to really stress that ligament and get after it, and we'll see how the arm reacts [Saturday]. That's a big part. It's going well and it's been a smooth rehab. I hope it continues that way."
Kemp, who is recovering from left ankle and left shoulder operations, wrapped up his morning workout by hitting breaking balls off a pitching machine and catching fly balls in center field. The outfielder will open the season on the disabled list.
"It was good to face him," Billingsley said. "He's working on things and we are trying to make each other better."
Kemp finished 2-for-4 with a home run and a double in a Triple-A game against the a White Sox.
"I'm getting my work in and getting ready for the season," Kemp said. "I felt pretty good. Today was a good day."
Jesse Sanchez is a national reporter for MLB.com. Follow him on Twitter @JesseSanchezMLB. This story was not subject to the approval of Major League Baseball or its clubs.