Asked how long he may refrain from throwing, Siegrist said, "it's not going to be long." He described the rest as "precautionary" and did make the other rotations around the field with his group on Monday to participate in non-throwing drills.
It is not all that uncommon for pitchers to experience arm soreness in the first days of spring as they begin conditioning their arms. General manager John Mozeliak said the Cardinals are unconcerned about this being more than just a minor bump in Siegrist's throwing program.
Siegrist, 24, comes to camp expected to be a key piece in the Cardinals' 2014 bullpen. Once a 41st-round Draft pick, Siegrist shot from Double-A to the Majors last season and dominated upon his arrival. In 39 2/3 innings, the lefty gave up 17 hits and two runs, struck out 50 and walked 18.
He's targeted to be a late-inning reliever for the Cardinals, who have only one other lefty (Randy Choate) already earmarked for a spot in the 'pen.
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.