Of the many variables that could influence the Dodgers’ World Series chances the rest of the year, one factor will be more important than all else.

The Dodgers need Tyler Glasnow to stay healthy, pitch well and — regardless of what they do before next Tuesday’s trade deadline — perform like an ace at the top of their rotation.

To that end, Wednesday was an encouraging sign.

After his first injury scare of the season, a two-week stint on the injured list because of back tightness, Glasnow made a much-needed return to the Dodgers’ rotation Wednesday night, giving up two runs in five innings during the Dodgers’ 8-3 loss against the San Francisco Giants.

Giants first baseman LaMonte Wade Jr. (31) slides around a tag attempt by Dodgers catcher Will Smith in the eighth inning on Wednesday at Dodger Stadium.

(Gina Ferazzi / Los Angeles Times)

Glasnow was far from flawless in his first start back from the IL. His command escaped him at times, leading to four walks. He exited with a deficit after giving up two runs in the fourth inning, including a solo home run to Matt Chapman. And if not for a couple well-timed double-plays, his overall stat line might have looked very different.

“My mechanics felt a little weird,” Glasnow said. “Not really in a good rhythm. Just the whole night was kind of a struggle.”

The Dodgers still lost, having their five-game win streak snapped on a night they failed to record a hit until the seventh inning (they did get one run on a bases-loaded walk in the first) and lost Chris Taylor (who had the knock with his seventh-inning double) to an apparent lower-body injury as he was running the bases — further underscoring their need to bolster the lineup ahead of next Tuesday’s deadline.

The game was close until the eighth inning, when the Giants exploded for six runs against relievers Yohan Ramírez and Joe Kelly to clear out most of a season-high crowd of 54,070 at Dodger Stadium.

Still, just having Glasnow — the Dodgers’ hard-throwing, high-profile acquisition this past offseason — back on the mound was a welcome sight for a pitching staff short on reliable October options at the moment.

“It never feels good to lose,” manager Dave Roberts said. “But the takeaway is that he feels good, he feels strong.”

Consider the state of the rest of the Dodgers pitching staff:

Yoshinobu Yamamoto is probably a month or more away from returning from a shoulder injury. Gavin Stone is having a strong rookie season, but has never pitched in the playoffs before. And while the Dodgers will be on the hunt for an “impact” arm in the next week, as general manager Brandon Gomes said this week, this year’s deadline market possesses few top options that will be easy (or cheap) to add.

Dodgers outfielder Teoscar Hernández leaps out of the way after getting hit by a pitch thrown by the Giants’ Robbie Ray during the first inning on Wednesday at Dodger Stadium.

(Gina Ferazzi / Los Angeles Times)

It means, in all likelihood, Glasnow remains the team’s best hope of being a legitimate front-line starter once the postseason arrives.

And between now and then, the team’s biggest priority will be keeping him healthy and pitching well — a tight needle to thread for a pitcher who is now just six innings away from last year’s career-high total of 120.

“As far as injury or health, I’m good to go,” Glasnow said. “I’m not thinking about it or anything like that. I think from now, it’s just go out and do business as usual.”

When Glasnow went on the injured list before the All-Star break, it conjured familiar concerns about his lengthy injury history — one that has limited him to just one 20-start season (which came last year) and only one extended October run, when he helped the Tampa Bay Rays reach the World Series in 2020.

As it turned out, his back injury was just as the Dodgers hoped: A minor ailment that, given his workload concerns, also served as a beneficial midseason break, giving him a couple of weeks off that should help keep his innings total under control.

Despite that, the Dodgers are still being mindful of Glasnow’s usage. Manager Dave Roberts said he will look for opportunities to “save” an inning every now and again in Glasnow’s starts. Another break at some point over the season’s final two months isn’t out of the question either.

The trick will be keeping Glasnow in form without overloading his workload.

As Wednesday showed, he remains the Dodgers’ most talented pitcher. But, even after a brief two-week absence, there was still some rust that needed to be knocked off.

“The innings usage, it is what it is,” Roberts said. “We can curtail an inning here or there. But once he takes the ball, we’re gonna go out there, pitch him and try to win a ball game … Today was one of those where there was a little more rust with the delivery, but I expect with another side [session] and another start in seven days, he’ll be where he needs to be.”

The Dodgers will have to hope so. It could be a defining subplot to the rest of their season.