With two outs and the bases loaded in the third, the 32-year-old was hit in the left calf on a hard line drive by John Jaso. Lackey was able to field the ball to get Jaso out at first and end the inning.
"I squared that one up," Jaso said. "That was right off the barrel. I saw it hit him, but I put my head down and ran. He made a great play on that. I went back and looked at it on replay and he made a great play."
Already down, 5-0, after he had given up two runs in the inning, Lackey was nearing more trouble when Jaso's liner nearly went by him up the middle for what would have been a run-producing single.
"I don't think it will affect [my next start]," said Lackey. "I told them I could keep going back out there, but obviously I wasn't pitching very well, so that wouldn't have helped us much anyway."
Lackey finished his 69-pitch outing with five runs allowed on five hits and was replaced after the inning by Scott Atchison, who was recalled before the game from Triple-A Pawtucket.
"It hit him good and caught all flesh," manager Terry Francona said. "It's sore. I'm sure he's going to feel like he got hit like he did. Hopefully it will subside enough that he can make his next start."
Chris Girandola is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.