Siegrist began feeling the tightness after his appearance on May 18, describing it as near his wrist. Before he made his next appearance May 24, Siegrist was unavailable out of the Cardinals bullpen on multiple occasions except in the case of an emergency.
After retiring all four hitters he faced against the Reds on May 24, though, the tightness hadn't subsided and Siegrist returned to St. Louis to have his pitching arm examined by team orthopedist Timothy Farley. While the results didn't reveal anything major, Siegrist was placed on the 15-day disabled list and given a program of rest and rehab.
He had appeared in 22 of the Cardinals' first 44 games before making his last appearance. In 23 outings this season, Siegrist has totaled 20 innings, allowing eight runs for a 3.60 ERA.
The Cardinals have relied on other arms in his absence. Manager Mike Matheny said Thursday's eighth inning, in which reliever Carlos Martinez allowed three runs to lose the lead in an eventual 6-4 loss to the Giants, would have typically been a spot the team would have gone with Siegrist.
If all goes well, Siegrist will be ready to return to those late-game situations next Sunday, when he's eligible to come off the DL.
"I would hope so, but I'm not going to rush anything," Siegrist said of being ready to return. "If I'm feeling something, it's better to get it right now than rush back and have trouble with it in the future."
Alex Halsted is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.