Red Sox placed RHP Justin Masterson on the 15-day disabled list with right shoulder tendinitis.
The Red Sox will place Justin Masterson on the disabled list with what manager John Farrell referred to as "arm fatigue."
Justin Masterson was shelled in a loss to the Athletics on Tuesday, surrendering six runs in 2 1/3 innings.
Justin Masterson gave up four runs and walked six in 4 1/3 innings Wednesday in a loss to the Rays.
Justin Masterson took a no-decision Friday against the Yankees after allowing two runs over six-plus innings.
Justin Masterson surrendered three runs in seven innings in Saturday's extra-innings loss to the Orioles.
Justin Masterson tossed five innings of one-run ball Monday as the Red Sox beat the Orioles in a rain-shortened game at Fenway Park.
Justin Masterson escaped with a no-decision, serving up seven runs in 4 1/3 innings as the Red Sox edged the Nationals 8-7 on Tuesday.
Justin Masterson surrendered two runs and three hits in six innings Thursday in a win over the Phillies.
Justin Masterson yielded two runs in five innings Saturday against the Twins.
Justin Masterson held the Orioles to one run in four innings on Friday.
Justin Masterson was pounded for six runs in 3 1/3 innings by the Phillies on Sunday.
Justin Masterson struck out four in three perfect innings as the Red Sox topped a Rays split-squad 5-1.
According to Rob Bradford of WEEI, Justin Masterson turned down a one-year $6 million offer from the Rangers to sign with the Red Sox.