Seattle, WA (SportsNetwork.com) - The Boston Red Sox placed starting pitcher Justin Masterson on the 15-day disabled list Thursday due to right shoulder tendinitis.

In seven starts this season, the right-hander is 2-2 with a lofty 6.37 ERA. He's allowed 40 hits and walked 19 in 35 1/3 innings.

The Red Sox have recalled left-handed pitcher Robbie Ross Jr. from Triple-A Pawtucket to replace Masterson on the roster.