The Cardinals believe this current discomfort is related to a nerve issue. Siegrist compared the discomfort to that which he felt the second week of Spring Training, when arm soreness forced him to skip a side session. That was hardly a setback, though, as Siegrist returned to the mound later that week and had no other arm problems all spring. He hopes this is the same.
"Everything else is fine," Siegrist added. "I think taking time off for my forearm de-conditioned my arm."
The tentative plan is to have Siegrist throw his next side session on Friday, though that is dependent upon how the next two days go. Whether he will then head out on a rehab assignment immediately has not yet been determined.
"We'll just have to keep watching and listening to the medical staff and figure out what the game plan is going to be," manager Mike Matheny said. "We'll go as slow as we need to."
Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, and follow her on Twitter @LangoschMLB. This story was not subject to the approval of Major League Baseball or its clubs.