4 things to watch in Chicago Bears-San Francisco 49ers game

(2) How will the Bears defense fare against 49ers quarterback Trey Lance?

Just like Fields, Lance is a promising young but inexperienced passer who was selected in the first round of last year’s draft—third overall by San Francisco. Spending most of his rookie year backing up veteran Jimmy Garoppolo, Lance appeared in six games with two starts and threw for 603 yards with five touchdowns, two interceptions and a 97.3 passer rating.

“You have to project how they’re going to use the young man and where they’re going to use him in their offense,” Eberflus said. “We certainly have an idea of what the offense looks like. But how they’re going to use him, no one really knows. You’re going to use your rules and have your calls and make sure you’re sound, what you’re doing.”

The 49ers no doubt feel the same uncertainty about the Bears defense. Sunday will mark the debut of a new 4-3 scheme that’s similar to the one that Eberflus coordinated the past four seasons with the Colts. Incorporating the “HITS” principle that Eberflus brought with him to Chicago, the Indianapolis defense focused on generating takeaways, swarming to the ball and playing with maximum effort.

The buy-in has come from the entire defense, which consists of several young, unproven players. “When you have those type of guys in the locker room and a good leader in ‘Flus’ and [coordinator] Alan [Williams] from the defensive side,” said linebacker Roquan Smith, “it makes guys want to buy in like, ‘OK, this is what it’s going to take? OK, we’re all for it. Let’s go.'”