Elias was pulled from his last start in the fourth inning on Tuesday in Anaheim after feeling some tightness in the elbow. He flew home to Seattle on Thursday and was examined by Mariners medical director Ed Khalfayan, who ordered an MRI exam Monday.
Manager Lloyd McClendon had indicated Sunday that there was an outside chance Elias might pitch in relief as a situational lefty if the MRI came back clean, but Monday's results mean the youngster now will be shut down until next spring.
In 29 starts this season, Elias was 10-12 with a 3.85 earned run average after jumping from Double-A to the Mariners rotation. The 25-year-old has thrown the third-most innings of any Major League rookie this season with a 163 2/3, trailing only Kansas City's Yordano Ventura (172) and Tampa Bay's Jake Odorizzi (165). He's fifth among MLB rookies in strikeouts and seventh in wins.
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB as well as his Mariners Musings blog. This story was not subject to the approval of Major League Baseball or its clubs.