Johnson went 2 2/3 innings, giving up three hits and a run in the Red Sox's 6-3 loss. He walked one and struck out four.
"It's my first time facing guys like that back-to-back-to-back, so it's exciting," said Johnson, who will likely start the season in Triple-A Pawtucket's starting rotation.
The Red Sox drafted the 6-foot-4 lefty with the 31st overall pick in the supplemental round of the 2012 First-Year Player Draft.
"I thought he was very sharp," said Red Sox manager John Farrell. "He throws multiple pitches for strikes. He throws the ball downhill, was at the bottom of the strike zone. Once again you see an above average curveball that he's able to finish off very good hitters with. And he grows on you because the stuff he has, the strike-throwing ability, the pace in which he works -- he's in command of himself on the mound."
Johnson seems very comfortable in his own skin.
"I'm just trying to have fun, man. Right now it's all about soaking it all in -- my first big league camp," Johnson said. "I'm trying to follow and watch guys and how they go about their business. When I take the mound, I'm not trying to change who I am. I just go out there and try to do the best that I can."
Ian Browne is a reporter for MLB.com. Read his blog, Brownie Points, and follow him on Twitter @IanMBrowne. This story was not subject to the approval of Major League Baseball or its clubs.