Chicago Bears linebacker Roquan Smith will be out indefinitely while dealing with a “personal issue” — and the organization has remained mysteriously silent as to what is going on with the second-year star.

About an hour before the Bears took the field against the Vikings on Sunday, fans and reporters were shocked to see Smith on the inactive list. Chicago’s leading tackler had practiced all week, had no reported injuries and was considered a vital piece of the game plan to stop the NFL’s leading rusher, Dalvin Cook.

Yet the Georgia product did not suit up, and instead watched the game from the sidelines in street clothes. Chicago gave no explanation other than Smith was dealing with a “personal issue” — a phrase that has been repeated ad nauseam over the past 48 hours.

The Bears would go on to crush their division rival 16-6, but the mystery surrounding Smith has only grown since Sunday — and answers are still jarringly scarce.

Bears coach Matt Nagy held a press conference Monday, and was asked 12 separate questions about Smith. Twelve separate times, Nagy gave some version of the party line — with that same phrase popping up yet again.

“It’s completely a personal issue,” Nagy said in response to one of the questions. “I’m not going to answer any more about it. That’s where it’s at right now. I understand where you all are coming from, but out of respect to this right now, I just want to leave it at that.”

When asked whether it was a legal issue, whether Smith faced any internal discipline or whether he would travel with the team to London this week, the usually candid Nagy repeated, time and time again, that it was a “personal issue” and he wouldn’t get into it.

Other details have been sparse. Adam Schefter told ESPN 1000 in Chicago on Monday that Smith had shown “erratic behavior” throughout the week and “was not acting like himself.” Schefter also shot down a rumor that Smith caused the car accident in a photo that had circulated on social media, as did a number of other sources close to the team.

ESPN insider Dan Graziano provided another small update on “Get Up” on Tuesday, repeating that Smith hadn’t been acting like himself and saying “it sounds like the kind of thing that could keep him out for a little while.”

Smith was supposed to attend an event at Maine East High School in Park Ridge, Illinois, on Monday night with teammates Prince Amukamara, Roy Robertson-Harris and Javon Wims, but pulled out.

Smith has been fantastic for Chicago since being drafted eighth overall in 2018. In 20 games, Smith has logged 153 tackles, five sacks and an interception. He was named to the PFWA All-Rookie Team in 2018 and seemed primed to make a Pro Bowl leap in his second season.

The Bears did prove last weekend that their defense can still dominate without him. With Smith sidelined, along with Pro Bowler Akiem Hicks and second-year lineman Bilal Nichols, Chicago still suffocated the Vikings on Sunday, holding Cook to just 35 yards on the ground.