"Last year he came back after the Tommy John and his arm speed was down a little bit, his velocity was down a little bit," Yost said. "He's back -- he was popping the ball at 90 to 92 miles an hour, great breaking ball, always had a great changeup. So he's back on track, which is really good to see. I'm excited for him."
Lamb, the Royals' fifth round pick in the 2008 First-Year Player Draft, spent most of last season with Class A Wilmington, but finished with Triple-A Omaha.
"It was a big outing for him to come out and pitch as well as he did," Yost said.
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.