"It's a relief," said Griffin, who experienced a similar problem over a week-long span in college three years ago.
The righty noted he felt fine in the bullpen and assumed he'd work his way through the discomfort that surfaced in the first. But "it just kept grabbing at me, and it was something where I couldn't get loose," he said.
Lefty Jordan Norberto came on in relief, which the A's were short on following Friday night's 15-inning marathon. The club's lone long man, southpaw Travis Blackley, pitched three innings in the contest, making him unavailable.
Six relievers were ultimately used in the A's 11-inning loss, so it's a safe bet the club will be calling in some help from Triple-A Sacramento for Sunday's matinee. That means Griffin could be bound for the disabled list, since the recently demoted relief pair of Jim Miller and Evan Scribner wouldn't be allowed back for another nine days unless an injury to a member of the big league club made it necessary.
Griffin's rotation slot, meanwhile, will likely be filled by righty Brandon McCarthy, who was slated to make his second rehab start with Sacramento on Saturday night. For Griffin, it was his eighth start forh the A's, who watched the rookie right-hander pitch at least six innings in each of his previous outings.