Jayson Tatum injury ‘could go down as one of the darker Celtic days’ — Bill Simmons makes grim prediction

Jayson Tatum’s injury could spell disaster for the Celtics — and not just for the series against the Knicks.

And Boston superfan Bill Simmons isn’t ignoring the potential enormity of the devastating injury blow, which the team and its fans still await full clarity on as of 2:45 p.m. Tuesday afternoon.

“Tonight was not a good night for Celtics fans, holy sh-t,” Simmons said of the team’s potentially franchise-changing Game 4 loss to the Knicks on his self-titled podcast Tuesday morning.

“This could go down — we’ll see what happens with Tatum — but this could go down as one of the darker Celtic days.”

Tatum’s injury came in the final few minutes of the 121-113 setback and it did not look good.

After going down with a non-contact injury, the 27-year-old Celtics superstar writhed in pain before being helped off the court, bearing no weight on his right leg and eventually being placed in a wheelchair.

“Not gonna speculate too much on the Tatum thing but it did not look good,” Simmons said. “Worst case scenario is an Achilles, best-case scenario is like torn ligaments in his ankle or some sort of bad ankle injury but, either way, done for the series, and God only knows how long.”

Tatum’s injury couldn’t have come at a worse time, either, as the reigning NBA Finals champs ended the night trailing the Knicks, 3-1, in the series.

But the trouble isn’t only for the current series in front of the Celtics, but also for the fact that Tatum is in the middle of what’s considered to be his prime.

“Not to mention, he’s at the peak of his career, he’s never had a major injury,” Simmons said. “If this is like a major one, it doesn’t just take him out for this playoffs, but it takes him out for, I think, all of next year too. You just wonder: Is he going to be able to get back to the point that he was at tonight?”

In Tatum’s eight years in Boston, he’s never played less than 64 of the 82 games in the regular season. But if the severity of Monday’s injury is as bad as many speculate, he will likely miss all of next season.

Simmons was visibly dejected while discussing Tatum’s injury and Boston’s waning back-to-back title hopes.

“We’ll see what happens with Tatum,” he said. “This speaks to: A) How hard it is to win a title. B) How important injury luck is. C) How hard it is to put together some really good years in a row.”