SAN FRANCISCO — When it comes to the Colorado Rockies' lineup this season, baptism by fire is the ritual that will cement — or perhaps sink — the team's October goals.

While the continued maturation of a young rotation, as well as the health and production of the team's stars — Nolan Arenado, Charlie Blackmon, DJ LeMahieu and Trevor Story — is also critical, the fact remains that manager Bud Black is putting serious faith in a handful of young, unestablished players to provide sparks for a slow-to-get-going offense.

That grouping within the Rockies' 25-man roster includes one true rookie in 26-year-old outfielder Noel Cuevas, plus an array of second- or third-year guys in outfielder David Dahl, 24, infielder Pat Valaika, 25, catcher Tony Wolters, 25, and infielder Daniel Castro, 25.

Though Cuevas (12-for-40, .300) and Dahl (17-for-57, .298) are off to decent starts at the dish in limited apperances, Castro, Wolters and Valaika have combined to hit .130 (19-for-146), and the five players have combined for just six home runs.

But none of those struggles raises major concerns for Black, especially considering no one in that quintet is a regular starter. Cuevas and Dahl have been platooning at the corner outfield spots with veterans Gerardo Parra and Carlos Gonzalez, Wolters is the backup catcher to Chris Iannetta, and Valaika — recalled Monday because of a thumb injury to LaMatheiu — has also been used mostly in a reserve role.

"They're understanding the difference between a big-league pitcher and a minor-league pitcher in a pinch-hit at-bat (and in intermittent starts)," Black said. "They're going through growing pains, and you learn from these situations. This is not anything they're not gaining from. Even though the statistical performance is not there for some, they're growing as players, and they'll be better off for it."

The question of whether the Rockies will be better off as a result — and whether sticking with those young players through early-season tribulations will bear second-half fruit — remains to be answered, but Black has consistently vouched for all of them, and there's no reason to think the manager won't continue to feed them opportunities.

Plus, down at Triple-A Albuquerque, first baseman Ryan McMahon, 23, and outfielder Mike Tauchman, 27, began the season with the major-league club. And they could fit into the Rockies' plans down the stretch despite their ice-cold starts (McMahon .180, Tauchman .043) to begin 2018 before being optioned.

"We felt as if those guys were ready, and as it turned out, they were probably ready mentally but physically — being in that role as a backup bench player getting at-bats here and there coming off the bench to pinch hit — that might not have suited them well in April," Black said. "I suspect they'll be back at some point to hopefully help us."

Notable

While in San Diego, Black discussed his managerial rule of thumb that if a player hits a home run, he's automatically in the lineup the next day. Black said he doesn't really stick to that anymore: "That's a pretty good rule that I had steadfastly adhered to, but you've got to be flexible. I started changing that rule a couple years ago, to a lot of people's chagrin." ... Expect Charlie Blackmon to be back in the starting lineup tonight in San Francisco after a day off for rest in Colorado's 4-0 loss to San Diego on Tuesday, in which the center fielder drew a walk as a pinch hitter in the eighth.