Lyon, who hasn't pitched a Grapefruit League game in more than a week, is scheduled to get an inning of work Monday against the Yankees in Tampa, Fla.
"After that first outing, I went out there and didn't give up any runs, but I didn't feel right," he said. "I wanted to get on the side and not worry about having a hitter up there. I decided I needed a couple of more bullpens, and it was good. I was able to worry about other things than getting people out."
Lyon's outing March 3 against Washington marked his first appearance in a game since June 13 of last year. He underwent surgery to repair the detachment of his right biceps tendon and to mend a tear in his labrum.
He said the work on the side has paid off.
"I feel really good now with everything," he said. "The ball's coming out of my hand pretty good, and I'm locating pretty well."