Justin Masterson battles sore knee
Masterson will throw a bullpen session in two days to evaluate the knee.
"We're going to back Justin up a couple of days," manager Terry Francona said, according to cleveland.com. "His right knee has been bothering him and he's been pitching through it, but it's hard for him to generate power."
Masterson is 4-5 this season with a 5.03 ERA.
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