According to KNBR thats going to the be the Giants rotation during the first three games.

Giants manager Bruce Bochy said Tuesday morning on San Francisco-area radio station KNBR that the team would go with rookie Madison Bumgarner or Tim Lincecum on three days' rest in Game 4 of the Division Series against the Braves, apparently leaving Barry Zito out of the mix.

Bochy did not say whether Zito would be on the postseason roster. They may choose to keep him as a long man in the bullpen, but he has never really filled that role, and they have gone most of the season without a true long reliever.

Zito is making $18.5 million this year, part of his $126 million deal that has turned out to be one of the worst contracts in baseball. Although he pitched well at times this year, including a seven-inning, two-run game against the Braves in his only meeting with them in August, he has not been good lately. Zito finished the regular season by going 1-8 with a 6.80 ERA in his last 10 games.

Presumably the Giants would go with Bumgarner if they are up 2-1 and Lincecum if they are down 2-1. The Braves are expected to do the same, either using Game 1 starter Derek Lowe or rookie Brandon Beachy.

Bumgarner, 21, was 7-6 with a 3.00 ERA in his rookie season. The only concern with him might be that he has thrown 193 2/3 innings, after throwing just 141 1/3 last year.

Lincecum has never started on three days' rest in the big leagues. If the Giants got to Game 5, they'd have Game 2 starter Matt Cain available on regular rest.
Bruce Bochy: Barry Zito Not in Giants' Rotation Against Braves -- MLB FanHouse