Trainers from both teams went to the mound. After about 2 minutes, Lester hobbled off with the assistance of Red Sox trainer Paul Lessard, and David Ortiz helped him down the dugout steps.
"It looked terrible; it sounded terrible," Boston Red Sox manager Terry Francona said.
It turned out to be not so bad.
X-rays were negative and Lester came away from Friday night's 9-5 loss to the New York Yankees with a bruised quadriceps. He hopes to take his next turn in the rotation.
"I'm fine. Any time you take a ball off any part of your body, you're worried, but the tests came back fine," said Lester, his right knee bandaged from mid-thigh to mid-calf.
He was able to bend the knee normally to put on his jeans.
"After what we saw, it was a big sigh of relief," Francona said. "It's pretty positive that he's going to be OK."
Cabrera wound up with an RBI single that gave the Yankees a 4-0 lead.
"It hit off my knee going about mach seven," Lester said. "It hit me in a good spot, where it didn't do too much damage that, hopefully, I won't miss any time."
Lester allowed five runs and eight hits in 2 1/3 innings. He has been Boston's top pitcher in the second half, entering the night 6-0 with a 2.44 ERA in 11 starts from July 25 on.
"Hopefully the swelling won't get too bad," he said.