The Dodgers placed starting pitcher Clayton Kershaw on the injured list Saturday, a night after he left a start against the Arizona Diamondbacks in the second inning with a bone spur on his left big toe.

Reliever Joe Kelly also went on the injured list with shoulder inflammation after throwing a season-high 46 pitches Friday night in relief of Kershaw.

In corresponding moves, the Dodgers called up Ben Casparius and Brent Honeywell Jr. from triple-A Oklahoma City. Both will be needed to provide length in a shorthanded bullpen that combined for eight innings in Friday’s win.

Kershaw’s placement on the IL was no surprise. Manager Dave Roberts said the 37-year-old left-hander has been dealing with his bone spur on and off for “years” and that it flared up Friday to the point where he struggled to push off the mound.

Roberts said the team wouldn’t have a better idea of Kershaw’s potential timeline to return until the swelling in his toe dissipates, but he’s hopeful Kershaw could return before the end of the season.

Friday was only Kershaw’s seventh start of the season after missing the first three and a half months recovering from offseason shoulder surgery.

He joins a crowded injured list that includes starting pitchers Tyler Glasnow (elbow) and Yoshinobu Yamamoto (shoulder) — both of whom remain at least several weeks away from rejoining the Dodgers’ rotation.

The good news for the Dodgers: Glasnow said Saturday he is “confident” that he will return before the end of the season, after coming away encouraged from two straight days of catch play.

“I’m feeling good,” Glasnow said. “As of right now, I feel great.”

When Glasnow first went on the IL on Aug. 16, there was little initial doubt about his long-term status. At the time, Roberts said Glasnow pushed to stay on the active roster. And the hope then was that he’d only miss the minimum 15 days required of an IL stint — which would have enabled him to return for this weekend’s pivotal series against the second-place Diamondbacks.

Dodgers pitcher Tyler Glasnow delivers during a game against the New York Mets at Dodger Stadium in April.

(Gina Ferazzi / Los Angeles Times)

After more than a week of not throwing, however, Glasnow’s elbow didn’t respond well to his first session of catch last weekend.

That raised questions about his potential availability for the end of the season — as well as his status for a possible October run.

When Roberts was asked Thursday if he could be certain Glasnow would return before the end of the season, the manager only said he was “hopeful.”

This weekend, however, the narrative has started to change.

Glasnow, who scratched a scheduled session of catch Tuesday before finally resuming his throwing program Friday, insisted he hadn’t experienced a setback, but rather that his arm just didn’t feel right after his initial break from throwing.

“I just think it was like tightness,” he said. “When you don’t throw for a while, everything kind of goes back to like a normal arm.”

The last two days, however, have been a different story.

“Everything feels clean, timing and mechanics feel good,” he said. “I just gave it a couple days and it feels good.”

Glasnow still has many boxes to check before rejoining the Dodgers rotation: Full-intensity flat-ground tosses, bullpen sessions and either a minor-league rehab assignment or live at-bats against hitters in simulated games, if not both.

“I don’t have a ton of time,” he acknowledged, “but I think it will be enough.”

Glasnow, who is aiming to make “a couple more” starts before the end of the regular season, said his main priority is being ready for the playoffs. To that end, he is hopeful that his recent absence — the second time he has been on the IL this season — will help him rectify some mechanical inconsistencies he’d felt prior to getting hurt.

“If there is any silver lining, I think taking the time off, you kind of get your body, it like resets back to normal,” he said. “Before I got hurt for a while there, I don’t think I was mechanically in a very good spot. I wasn’t moving how I used to move. Now, kind of going back to zero and then ramping back up, I’m like, ‘Oh, that’s the feeling I’m trying to feel.’ I think once I iron out a lot of that stuff, a lot of the other issues go away.”

The Dodgers will certainly be hoping so.

When they acquired Glasnow this offseason and signed him to a five-year, $136.5-million contract, they were banking on him to anchor their October rotation.

While his road getting there has been bumpy — despite a 9-6 record and 3.49 ERA when he’s been healthy — Glasnow still feels capable of shouldering such a critical load.

“That’s why I came here,” the 31-year-old said. “That number one priority is just the World Series. That’s like all I think about now, at this point in my career.”