ATLANTA -- The San Francisco Giants changed course late Sunday and will place Matt Cain on the 15-day disabled list, scrapping plans to start the right-hander in Monday night's series opener at Pittsburgh.

Right-handed reliever Jake Dunning will be recalled from Triple-A Fresno on Monday to fill Cain's spot on the active roster, assistant general manager Bobby Evans announced.

Cain was scratched from his scheduled start against San Diego last Tuesday when he cut the tip of his right index finger with a knife while making a sandwich before the game.

Yusmeiro Petit replaced Cain and threw six scoreless innings in the Giants' victory over the Padres.

In the following days, all indications were that Cain would rejoin the rotation on schedule and start the opener of the Pirates series as the streaking Giants, winners of nine of their last 10 games, continue a three-city road trip after a sweep in Atlanta.

On Sunday, Cain was officially was named to start and Cain said that he would be able to pitch without restrictions, a statement that was affirmed by Giants manager Bruce Bochy.

Cain's disabled list placement will be retroactive to April 25, meaning he could come off and face the Dodgers in Los Angeles next weekend.

The Giants have not announced who will start Monday in Pittsburgh, but they will likely call on Petit again as a fill-in rather than move up in the rotation Tim Hudson, who would be working on his regular four days' rest because of last Thursday's day off.

Cain, who has made just one other trip to the disabled list in his career, is 0-3 with a 4.35 ERA in five starts this season and that is reminiscent of 2013, when he went 0-2 with a 6.39 ERA during April.

Cain, however, was 4-0 last May before leveling off to go 8-10 with a 4.00 ERA.