SANTA CLARA — There’s no more pressing decision for the San Francisco 49ers than the names that will make up the passenger manifest for Wednesday’s globe-crossing flight.

Who gets on the plane will determine who has a chance of playing in their season opener against the Rams a week later, next Thursday in Melbourne, Australia.

And with two days until departure, the Niners know more about George Kittle than Nick Bosa.

Kittle, who tore his Achilles tendon on January 11, took a massive step in his recovery this week when he rejoined the team for 11-on-11 drills. That happened Monday, per GM John Lynch.

Bosa, who had his ACL in his right knee surgically repaired for the second time last September, still hasn’t gotten there. While Kittle has been a visible participant since returning to practice last Sunday — and made his presence known even while he was physically incapable — Bosa has been mysteriously absent, even as his ramp-up was supposed to intensify this week.

Could it really be possible that Kittle, less than nine months removed from his injury, has lapped Bosa, who got hurt four months earlier, in their rehabs?

Of the two, it sure looks like he has the better chance of suiting up next Thursday.

According to Lynch, Bosa’s work has been happening behind the scenes. The plan, the general manager said Tuesday morning on KNBR, was for him to get on the field Wednesday.

“Is it ideal? No,” Lynch said. “But I will tell you … he’s been tracking very well. Now, always ramping it up to actual football is a difference, so that’s the next step.”

Those are either the words of someone supremely confident in Bosa’s ability to be game-ready from Day 1, or somebody who already knows there’s not much hope of him playing Week 1.

Because by the time the 49ers get off the practice field Wednesday, there will be just hours left before they head to the airport for an 8,000-mile flight to the other side of the world.

They won’t have time to evaluate Bosa’s day, let alone how his body responds 24 hours later.

When Bosa initially returned to practice at the start of training camp, he had to be shut down because his knee flared up upon the increase in activity.

There’s only one way to know if that happens again, and by then, the Niners will be halfway around the globe at an elevation of 40,000 feet, well on their way to their temporary home for the next week.

Kittle was upfront about what he needed to do to convince himself that he would be ready for Week 1. He needed to put pads on and experience the physicality of the sport again.

He did that Monday, when he returned to team drills.

Bosa has yet to reach the same goal post, and he has only one more chance before wheels up.

Given the time constraints, maybe it’s already a given that Bosa makes the trip. The same can’t be said for his status for gameday, not without seeing him on the practice field for almost a month.

There’s an argument to be made that Bosa’s presence is more important than Kittle’s. Without him last season, the Niners ranked last in sacks. And they’ll be without their other top pass rusher, Mykel Williams, who’s out until at least Week 5 on the Physically Unable to Perform list.

For that reason alone, Bosa’s ticket could’ve been punched long ago. The 49ers pulled off a similar stop-and-start with Christian McCaffrey, who’s already back at full speed after missing a chunk of camp. It would also make more sense to slow-play Kittle’s return, given how far ahead of schedule he already is.

And yet, Kittle has been the one more involved at practice so far this week. Bosa has been invisible.

The Niners hold their first practice in Melbourne on Saturday local time and get two more after that before kickoff. Defensive coordinator Raheem Morris seemed to indicate that those sessions would determine whether or not Bosa is cleared to suit up for the season opener.

“For me to feel comfortable, it’s different. It’s more about Bosa,” Morris said. “What does Bosa need? … Bosa’s got a plan in place. I don’t want to reveal it if Kyle hasn’t done it. But obviously they’ve got a real legit plan … an all-hands on deck mentality to get him ready to go.”

To get a sense of how little roster maneuvering will be available to Lynch and Shanahan once they land, listen to this: They’ve had to add an extra question for any player San Francisco has considered signing to the practice squad — got a passport?

“Those are questions we have to ask now,” Lynch said. “There’s a lot of little logistics like that that are complicated by this.”

And a few big things, like the health of two of their most important players.