The only place to see the Bears’ starters play a full game this preseason was on Field 3 behind Halas Hall.

On Wednesday night — on just more than 24 hours’ notice — that’s where the Bears created their own game.

They rented stadium lights, powered by generators, for when the sun went down beyond the forest that borders two of the field’s four sides.

Players ran onto the field as if they were shot out of the tunnel. Their DJ turned the volume knob to 11 and played crowd noise and familiar Soldier Field sounds from game day. “Bear Down, Chicago Bears” rang through the night after touchdowns.

When the starting defense was on the field, it was the “Bear Raid Siren.”

“I love that thing,’’ coach Matt Nagy said. “I think it’s awesome.”

The Bears’ starting offense and defense each played 60 plays against backups, all scripted by the coaching staff. The Bears ran through every conceivable special-teams scenario. About halfway through, a light rain began to fall.

If it sounds like a replacement for a preseason game, that’s because it probably was. Nagy doesn’t figure to give his best players much game action this preseason, an escalation of his radical plan from last year to keep his players healthy.

“They got a lot of reps out here tonight,” Nagy said. “And, uh, I like that they got a lot of reps.”

Nagy told his team about the practice game during the team meeting Tuesday afternoon. In doing so, he pushed back Wednesday’s 8:15 a.m. practice to 5:45 p.m.

The Bears didn’t hold a practice game last preseason — but they also had more live action, playing five preseason games and holding a two-day joint practice in Denver.

“Every coach is different; every player is different,” Nagy said. “I, personally, think it’s good to add to what we’re doing for our specific team. But there’s a lot of coaches out there that want to play their guys a lot, and there’s nothing wrong with that.

“And I don’t personally think there’s anything wrong if you don’t want to play your starters as much as some others.”

The game fell somewhere between live and simulation. They played “thud” — in which players can make contact with ball carriers but not tackle them. Danger still lurked behind every snap — Cody Whitehair left with an injured finger on his left hand, and fellow guard Kyle Long’s practice ended early after he swung a helmet at teammate Jalen Dalton — but there was far less risk than there will be Friday night against the Giants.

“Well, for us, any simulation you can get, in a controlled environment — that word ‘controlled’ is huge,” Nagy said. “And I think when you get a controlled environment like we have — whether it’s the first team or second team or third team — you can have your guys out here playing a full game.”

Without exhibition games to juice up the doldrums of the preseason, veterans appreciated the practice.

“It was just a good switch-up for camp,” cornerback Buster Skrine said.

Running back Mike Davis said he looked at the practice as the offense helping the defense grow, and vice versa. Inside linebacker Danny Trevathan said there was enough contact to keep things interesting.

“I feel like it was just great work for us — a game environment, guys getting some good reps,” Trevathan said. “Just taking care of our responsibility and having fun. That’s all it’s about, man.”