Trying to remain hopeful, Smith called his departure from the game a "precaution." Manager Bruce Bochy was not as upbeat.
"We're looking at some time [for being sidelined]," Bochy said.
Should Smith open the season on the disabled list, San Francisco's other left-handers obviously would move up in the bullpen pecking order. Steven Okert, who has allowed one unearned run in seven outings, almost surely would make the Opening Day roster. Josh Osich, who walked three batters in the sixth inning and allowed a run, still would receive strong consideration. So would Ty Blach, who could be used in multiple roles, including long relief.
Chris Haft has covered the Giants since 2005, and for MLB.com since 2007. Follow him on Twitter at @sfgiantsbeat and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.