Giants manager Bruce Bochy indicated Albert Suarez, who pitched five capable innings in relief of Cain on Friday, is the likeliest candidate to replace Cain on Wednesday in Atlanta. Stratton will assume the long-relief role that had belonged to Suarez. But Bochy said he won't hesitate to use Suarez before Wednesday if he needs the right-hander in relief.
"We'll make the call in a couple of days," Bochy said of Wednesday's starting assignment.
Cain, who was sidelined with a strained right hamstring two years ago, conceivably could miss just one start if he's able to recover during the 15-day DL period. The Giants will need a fifth starter on Wednesday, but due to scheduled off-days June 6 and June 9, they wouldn't have to use their No. 5 man again until June 14. Ideally, Cain would be healthy by then.
But Bochy almost always keeps the rotation intact through off-days to give all of his starters extra rest and declines to skip starters on the back end of the rotation to maximize the number of outings for his top pitchers. Thus, whoever temporarily inherits Cain's spot likely will start twice, possibly three times.
Cain pitched 1 2/3 scoreless innings Friday before sustaining his injury and leaving the game. He recently had regained the effectiveness he displayed in bygone years, recording a 1.71 ERA in his previous three starts after posting a 7.84 ERA in his first six outings of the season.
San Francisco's first-round selection (20th overall) in the 2012 Draft, Stratton owned a 5-4 record with a 6.02 ERA in nine starts at Triple-A. He actually improved when he ascended from Double-A to Triple-A last year, finishing 1-5 with a 4.14 ERA at Richmond before posting a 4-5 mark with a 3.86 ERA for Sacramento.
"I guess they saw that I've been working pretty hard," said Stratton, who credited sharpened fastball command for hastening his development.
• Bochy said he expects center fielder Denard Span to rejoin the lineup Sunday. Span was scratched from Saturday's lineup with a bruised right hip he sustained when he collided with AT&T Park's outfield wall late during the club's last homestand. Gregor Blanco replaced Span in center field and at the top of the order.
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.