Programming note: Giants-Cubs coverage starts today at 4:30 p.m. with Giants Pregame Live on CSN Bay Area.
Mike Leake has made one start for the Giants since San Francisco acquired him on July 30.
It's unclear when he will take the mound again.
Leake will not pitch against the Cubs on Friday because of a mild left hamstring strain, the club announced Thursday afternoon.
Ryan Vogeslong, who last started on July 11 against the Phillies, will get the ball in his place.
Leake allowed two runs over 6.