San Francisco Giants starting pitcher Jeff Samardzija is reportedly expected to start the 2018 MLB season on the disabled list after being diagnosed with a strained right pectoral muscle.

Henry Schulman of the San Francisco Chronicle provided the update Thursday night and passed along comments from optimistic Giants manager Bruce Bochy.

“He’ll go a week without throwing the ball and then crank it up,” Bochy said. “It shouldn’t take long for him to get back on the mound, so that’s good news.”

This is a difficult setback for San Francisco and Samardzija as he looks to bounce back from last year’s up-and-down performance. He compiled a 4.42 ERA across 32 starts in 2017.

Samardzija signed with the Giants before the 2016 season after a lackluster 2015. He was an All-Star in 2014, when he posted a 2.99 ERA, a 1.07 WHIP and 202 strikeouts in 219.2 combined innings for the Chicago Cubs and Oakland Athletics. However, that marked a career-high workload, and he suffered a drop-off in 2015 with the Chicago White Sox, finishing with a 4.96 ERA in 214.0 innings.

He didn’t regain his All-Star form in his first year with the Giants but still posted a solid 3.81 ERA in 2016.

Fortunately for San Francisco, the depth of its starting rotation is one of its strong points. It still has Madison Bumgarner and Johnny Cueto as a formidable one-two punch that should keep the team afloat until Samardzija returns. Meanwhile, Derek Holland should get the first crack to fill the void.