HOUSTON — It’s probably not fair, and almost certainly not accurate, to pin the Cubs’ recent struggles on one player.

But it’s also nearly impossible to overlook the increasing impact Ben Zobrist’s absence is having on the Cubs three weeks after he took a personal leave.

“There’s a lot of moving parts within that one,” manager Joe Maddon said. “It absolutely has an impact.”

And as the Cubs push through the toughest part of their schedule to date without the versatile veteran and significant clubhouse voice, they also are forced to consider the possibility of playing the rest of the season without him.

“I have to think that way, absolutely,” Maddon said Tuesday, exactly three weeks after Zobrist took leave to tend to family issues, which have since involved divorce filings by him and his wife.

“I hope that’s not the case. But he’s at the point now where if he chose to come back, it’s going to take him awhile to get back up to speed, too. We have to mentally be prepared that we will not have him.”

That could be a big blow to a first-place team that fell to 11-10 without him after losing 9-6 to the Astros for their third straight loss and ninth in 14 games.

Pitching has played a key role in the more recent struggles — including a third consecutive clunker by Jon Lester (0-3 with 16 earned runs allowed in 14 combined innings in those starts).

But the ripple effect on the lineup has had an impact, too. Kyle Schwarber’s two-week run atop the batting order is a direct result of not having Zobrist as a matchup option, said Maddon, who added that Zobrist would have started the last two games. He matches up well with the Astros’ pitching style and always has hit well in Houston.

And whatever percentage of impact you want to apply to this one, consider that the Cubs’ team batting average with men in scoring position is down more than 100 points from its .284 mark before he left.

They went 0-for-9 in that situation, dropping them to 25-for-144 (.174) in 21 games without Zobrist.

“Ben has always been a big part of the team,’’ Schwarber said. ‘‘He’s been a guy who always puts in a professional at-bat every time he’s up there. He’s a contact guy, too, so without him here, obviously we miss him. But we still have to do our job.

“But he’s missed.”

Maddon, Schwarber and other teammates and team officials say they have no idea when or if Zobrist will be back, giving him his space while occasionally texting their support or — as was the case Sunday — birthday wishes.

“He’s one of our guys, one of our best buds, on and off the field,” first baseman Anthony Rizzo said. “He brings a tremendous professional approach every day. As younger players, you look at Ben, and he’s a constant professional.”

And on this road trip in particular, to Houston and St. Louis, with Kris Bryant and Jason Heyward coming off their collision Sunday afternoon in the outfield, the Cubs might be able to use Zobrist like no other time since he left.

He has a .386 on-base percentage and .457 slugging percentage in 17 career games at Minute Maid Park and is even better at Busch Stadium in St. Louis: .317 with a .389 OBP and a .475 slugging percentage in 28 games.

“Schwarbs has done a nice job with the leadoff spot, but quite frankly had Zo been here, he’d have been in that leadoff spot more often against right-handed pitching,” Maddon said. “And if you like Schwarbs there, he could have been down in the lineup protecting somebody a little more, moving the ball, maybe in the 5-hole, like we did in 2016.

“And then game in progress, what you can do with game in progress, moving people around comfortably, we miss that. And last point, purely his professional at-bat. It’s wonderful when our guys get to see that all the time.”