Barring any setbacks in the next two days, Cain will make his scheduled start in St. Louis against the Cardinals' Michael Wacha on Saturday.
Cain exited his May 21 outing against Colorado after three innings with a strained right hamstring.
Reliever Santiago Casilla also threw prior to Wednesday's game. On Tuesday, Bochy praised Casilla's work ethic during his recovery and said Casilla could return sooner (four weeks) rather than later (six weeks) from the strained right hamstring he suffered last week against Colorado. Wednesday, Bochy cautioned against the pitfalls of a rushed return.
"He's starting to feel giddy and you've got to back him off a little bit," Bochy said. "If you [injure] it again, the second time takes longer and is worse, so we have to be careful with him."
Casilla has a 1.37 ERA in 22 appearances this season.
Ryan Hood is an associate reporter for MLB.com. Alex Espinoza is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.