Most Bears starters won’t play Sunday’s preseason opener against the Miami Dolphins. Quarterback Caleb Williams is unsurprisingly among the roughly 18 first-teamers who won’t suit up for the exhibition at Soldier Field.

There will be someone as integral any fully participating in this affair.

Head coach Ben Johnson.

This will be the first time the rookie head coach will manage a game, in addition to offensive play calling responsibilities. Johnson has been preparing several months for such important responsibilities, where his decisions will have a significant impact on the game.

Johnson has been going over analytics and scenarios as part of his working routine, but this will be the first time it happens live. That’s why this preseason slate is as important for him as anybody, and fans should expect Johnson to use challenges and timeouts as if it was a regular-season game.

“We’ve done a lot behind the scenes so far in our walkthrough settings, in terms of very specific situations that both educate the players and allow the coaching staff to get on the same page with what’s going on and what some of the words mean,” Johnson said on Friday. “Because once you get into crunch time and, the guns are going off, then we just want to make sure that one word tells everybody exactly what’s going on.”

Johnson’s in a new position on game day, and this coaching staff must figure out how to work well together in terms of communication and game-day responsibilities. The Bears coaching staff has three games to figure it out.

They did a dress rehearsal during Family Fest on Aug. 3, when the coaches communicated through headsets and tried to mimic a full pre-game warmup. There will be kinks to work out so they’re ready for Week 1 against Minnesota.

“It’s been a learning process because it’s our first year doing it all together,” Johnson said. “I think the guys have handled it really well so far, but we’re going to put ourselves in those situations as much as we can, whether it’s in walkthrough or full speed practice. That’s really why I’m excited about these preseason games is that’s naturally going to occur organically.”

Johnson has a number of great resources on staff, but defensive coordinator Dennis Allen is one who can help him through the challenges of being a game manager and a play caller at the same time. Allen has been a head coach with the Raiders and Saints, and has experienced what Johnson’s going through now.

“It’s all dress rehearsal for the regular season,” Allen said last week. “I think all of us will learn—players, coaches, everybody alike. We’ll have to make sure we’re good on our communication, from the booth down to the sideline, whoever that is and whoever we’re having to communicate with. We’re excited about having our first preseason game. We’ll have to sort out some of the kinks and try to improve for Week 2.”