This could be when the “too good to be true” moment arrived for the 2017 Los Angeles Dodgers.

There they were, stampeding through the season, threatening to eclipse records for “games won” in Los Angeles (102) and even Brooklyn (105), and then on a Sunday afternoon in Chavez Ravine left-hander Clayton Kershaw, walked out of a game in the second inning with lower-back pain, and the long-term fitness of their best player is in question again.

Having an 11.5-game lead in the National League West, as the Dodgers did at the end of the day, is a bit of comfort in terms of a playoffs appearance, but when a team loses the best pitcher in ball, well, there’s no replacing “the best”, is there?

Let’s look at this two ways: One is via the Notions of an Amateur Back Specialist; the other is where Kershaw and the Dodgers might be heading.

Kershaw is 29, or about the same age I was when I developed lower-back problems that persisted for years.

But, then, most of us have back problems eventually, and we know how debilitating they can be. I remember the pain being so intense that I spent a week draped over a footstool in the living room because that position seemed to pull something away from contact with something else, lessening the pain. It was the only time that I lost to “sickness” in my professional career.

It took me a while — years, actually — but I am fairly sure I figured out the root of my problems.

We had young children, and to amuse them as well as get some exercise I would put one of them in a backpack and take a ride on a bike. The kids almost always would nod off, and I would pedal in silence … but I also was carrying 15-20 pounds that was tweaking my spine.

When I finally gave up the backpack, mostly from the kids being too big to carry in it, my back pain and the attendant sciatica went away.

Well, duh. But during those years when I was pedaling for an hour-plus with a batch of unstable weight attached to my shoulders it did not occur to me that it was that form of exercise that was the issue.

In Clayton Kershaw’s case, we have a pretty good idea of what his back pain is about.

Pitching.

Last season he missed 75 days with what was called a herniated disc in his back. He came back from it in time to pitch in the playoffs and he worked on it throughout the offseason to get him ready for 2017, and he was doing fine. Until today.

My amateur observations lead me to wonder if Kershaw’s curious delivery is part of the problem. You have seen it, and you wonder how he can throw strikes, considering all the things he does with his right leg. Here is video of it, including some in slow motion.

First, the right leg comes up fairly high, to where his right knee is almost at chin height. Then he drops the leg to a few inches off the ground, but asks his back to hold it there, in mid-air, as he shifts his weight and continues with his pitch.

That strikes me as something far less than a normal motion for the human body. And I feel pretty strongly that if he stopped pitching, the pain very possibly could go away, never to bother him for years or decades (which has been my experience, thank goodness).

But pitching is what he does. My cycling trips with a child on my back … I did not get paid for that. It was fun but it was not a job requirement.

Kershaw does not have that luxury. He throws baseballs for a living, with a strange motion, and we may have reached a point where his back is just not able to bear the stress of a full season … and the pain may become more common.

(A sidebar. A guy who blogs about the Dodgers had a chat last season with his brother, a neurosurgeon who knows things about backs, and the conversation can be read here. It tells us how an epidural injection was about dealing with the pain, not curing a herniated disc, and how “rest” is one option and “surgery” is another. The problem with the latter is that Kershaw would have missed the rest of the 2016 season.

We are told that the pain is not so bad for Kershaw this time. Medical people around him say it is not a disc issue but a muscular one. Still, the Dodgers are saying their ace will be out four to six weeks, and anyone who follows injuries in Major League Baseball knows “four to six” can easily stretch to eight or 10 … and then he is out of the postseason.

Losing Kershaw does not mean the Dodgers are doomed to an early exit from the playoffs.

For one, he could be back in September, as he was last year. For another, they went 38-24 without him last year and climbed from eight back of San Francisco to a five-game lead. He takes with him 15 victories, but the team is 54-29 this season in games where he did not get a decision. No need to panic.

So, let’s think long-term here.

Kershaw now has had back injuries requiring a month or more on the shelf in consecutive seasons — after 16 starts and 121 innings a year ago, after 21 starts and 141.1 innings this season. We have to consider the possibility that this is the new normal for him — a situation when he could hurt it at any time, but specifically when he is in his second hundred innings.

Worst-case scenario? We have seen the end of peak-level Clayton Kershaw.

He is only 29 years old, but the Dodgers have ridden him pretty hard since he joined the team in 2008: Nearly 2,000 innings pitched (1,982.1), counting his postseason totals, with a 155-69 record (again, including playoffs).

He is 13th all-time in IP for the franchise and not far behind the two guys who led the club during the 1980s and 1990s — Fernando Valenzuela (2,348.2) and Orel Hershiser (2,180.2). And he is well ahead of any Dodgers pitcher in IP since the mid-1990s; Hideo Nomo is next in IP, at 1,217.1 with the club.

This website has Kershaw sixth in “wins above replacement” (WAR) among everyone who has played for the franchise, with 57 WAR — only eight short of Don Drysdale at the top of the heap.

Kershaw has been really really good for nine seasons, and that may be about all we can expect from someone. A left-hander often compared to Kershaw, Sandy Koufax, pitched 2,324.1 innings but had only five peak seasons before elbow pain drove him out of the game at age 31.

What the Dodgers and their fans hope is that Kershaw recovers and finds some exercise regimen that allows him to pitch from opening day till the end of the season. But that may not be reasonable.

Concede it: You as a fan knew this would come some day, when Clayton Kershaw got hurt. You thought it more likely to be a shoulder thing or an elbow thing but, instead, it is a back thing which is, in a way, scarier than a shoulder or elbow because back surgery seems less of a sure cure.

More of elite Clayton Kershaw would be nice. It also may not happen and the Dodgers should be thinking, right now, about winning things without him.