"I don't think Loewen is going to pitch when the 15 days on the DL is up," Trembley said. "I think we're looking at longer than that. How much longer than that, I'm not smart enough to make that prediction."
Loewen, who was limited to six starts during a 2007 season cut short by surgery to repair a stress fracture in his left elbow, was placed on the 15-day disabled list on Friday, a day after he couldn't get out of the third inning in Seattle. He is 0-1 with a 7.85 ERA in four starts this year.
The Orioles opted to disable Loewen as a precautionary result after he reported forearm pain in his last start. He underwent a CT scan and an MRI test Monday.
"We don't have the results back of that yet," Trembley said, adding that team orthopedists Dr. John Wilckens and Dr. Andrew Cosgarea will consult with Birmingham, Ala.-based surgeon Dr. James Andrews once they have viewed reports of the examinations.
Pete Kerzel is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.