Clayton Kershaw may not be ready to pitch in Dodgers’ season opener

Reporting from PHOENIX —  Dodgers manager Dave Roberts acknowledged for the first time on Monday that ace Clayton Kershaw, who has been slowed this spring by shoulder inflammation, may not be ready for the March 28 season opener against Arizona.

Roberts named Kershaw as the opening-day starter on Feb. 19, the first day the Dodgers held full-squad workouts. The next day, the three-time National League Cy Young Award winner’s shoulder flared up, and the left-hander stopped throwing for four days.

Kershaw has made a franchise record eight consecutive opening-day starts. Robin Roberts of the Philadelphia Phillies holds the major-league record with 12 consecutive opening-day starts for one club. Hall of Fame right-hander Jack Morris has the overall mark, making 14 opening-day starts with the Detroit Tigers, Minnesota Twins and Toronto Blue Jays.

Kershaw resumed throwing last week and played catch from 60-70 feet for the fourth time in five days on Monday. He has put more intensity and effort into each of his throwing sessions, but there is no timetable for him to throw off a mound, the next step in a progression that will include several bullpen sessions.

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To make the four exhibition starts required to build up enough endurance to throw five or six innings in a regular-season game, Kershaw would have to pitch in a spring-training game by Friday.

“That’s fair,” Roberts said, when asked if it would be difficult for Kershaw to be ready for the season opener. “The main thing is he’s trending in the right direction, and when he’s game-ready is when he’s game-ready.”

The Dodgers have more than enough rotation depth to absorb the loss of Kershaw for the first week or two of the season. Though Roberts said the team is still “hopeful” Kershaw will be ready for opening day, it is not imperative that Kershaw make his ninth straight opening-day start.

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“There’s just way too much importance put on the opening-day roster,” Roberts said. “The No. 1 thing is for him to be ready and to feel confident physically and mentally, and when that is, it is.

“We feel very comfortable that he will get ramped up, and regardless of when that is, there’s a lot of talent in that room that he’s surrounded by [that can ease his loss].”

mike.digiovanna@latimes.com

Twitter: @MikeDiGiovanna