SAN DIEGO —The rookie it is.

Manager Bruce Bochy said that Ty Blach would start in place of injured Johnny Cueto against the Padres on Sunday unless he were needed in relief Saturday night. Blach got the nod over Matt Cain and Jake Peavy , who started the year in the rotation.

“I’d say this in fairness to Jake and Matt,” Bochy said. “Blach got more starts and consistent innings in Triple-A, every fifth day. Those guys are getting work here and there. We think Blach is more suited to make a start. He’s been stretched out. He’s good to go.”

Blach, who turns 26 in October, has not allowed a run in two three-inning relief appearances, at Coors Field and Dodger Stadium. His 3.43 ERA ranked fifth in the Pacific Coast League.

Blach repeated Triple-A and had fallen in the Giants’ prospect rankings, but he surged in 2016 as he gained more experience and added a different curveball to go with his changeup.

Dwight Bernard , Sacramento’s pitching coach, said he believes Blach’s willingness to listen and change fueled his improvement as well.

“When a kid is as receptive as he is, with the stuff and the confidence he has in the stuff, he’s got a chance to be successful,” Bernard said. “He’s probably not a world-beater, but he’s going to go out and compete.”

Blach will be the first left-handed rookie to start for the Giants since Mike Kickham in 2013. Eric Surkamp was the last to win, in 2011.

Cueto’s return is not imminent. Bochy said after Saturday’s game that Cueto will not even try to throw off a mound until Tuesday.

Crawford on Sunday? Brandon Crawford said he still hopes to return from his dislocated pinkie Sunday. He had hoped to take batting practice before Saturday’s game.

Crawford hit off a tee Friday and said he felt less pain than he expected, but playing catch felt worse than he expected. He plans to place the pinkie and ring finger into the same glove finger to prevent the injured digit from bending.

Crawford was injured Tuesday night. Two years ago, Joe Panik returned sooner after a similar injury.

Henry Schulman is a San Francisco Chronicle staff writer.

Leading off

Suarez feat: Although he lasted just four innings, Albert Suarez on Friday became the first Giant in the live-ball era to start his career with 12 games allowing no more than three runs.

— Henry Schulman

On deck

Sunday

at Padres

1:40 p.m. CSNBA

Blach (0-0)

vs. Richard (3-3)

Monday

Off

Tuesday

vs. Rockies

7:15 p.m. CSNBA

Marquez (1-0)

vs. Moore (11-12)