The A's right-hander struck out nine and allowed two hits over six shutout innings Saturday night before Triple-A Sacramento posted a 3-2, 10-inning victory over Memphis.

Recovering from right shoulder issues that plagued him for much of the season, McCarthy struck out five of the first six Redbirds he faced, including all three in the second inning.

After allowing a leadoff double to Cedric Hunter and walking Jose Garcia in the third, he caught Nick Derba looking at a third strike and got Adron Chambers to ground into an inning-ending double play. McCarthy faced similar issues in the fifth with two runners on and one out, but a strikeout and popout avoided any damage.

Seven of the 29-year-old's nine punchouts were looking. He threw 47 of 73 pitches for strikes.

The start was a stark contrast to McCarthy's first rehab outing with the River Cats on Monday, when he surrendered six runs on seven hits in 3 2/3 frames.

With a quality start under his belt, McCarthy could be ready to return the big club. Earlier Saturday, A's No. 12 prospect A.J. Griffin, who's 3-0 with a 2.42 ERA in eight Major League starts, left Oakland's 11-inning loss to Toronto with shoulder soreness. Results of an MRI were negative, but a trip to the disabled list is possible.

That could leave McCarthy as the natural fit to fill the vacancy in the rotation. A roster move would depend on the veteran's health following Saturday's outing.

While the A's fell in 11, the River Cats provided the kind of late late-inning heroics to which Oakland fans have grown accustomed.

After Memphis' Steven Hill homered in the ninth, Anthony Recker plated Josh Donaldson with a walk-off single in the 10th.