Chicago Bears quarterback Caleb Williams experienced plenty of learning moments as a rookie last season. A lot of those came against the Minnesota Vikings.

One of those “welcome to the NFL” moments occurred against Minnesota when Williams played a game of mental cat and mouse against Vikings safety Harrison Smith.

Williams checked to a new play during a drive when he saw how Minnesota’s defense was aligned. Smith quickly reacted to the check and adjusted his defense’s formation to another play call.

The move forced Williams to go through mental gymnastics and check his play once again.

“There’s plenty in that game of cat and mouse, and [Smith’s] been doing it for so many years,” Williams told reporters at Halas Hall in Lake Forest on Wednesday. “They got a bunch of good guys over there – [cornerback Byron Murphy Jr.], they obviously got the new guys on the [defensive line]. And then also [linebacker Jonathan Greenard], he’s a beast. Being able to maintain those guys and go out there and execute our game plan and being able to go out there and be efficient with the ball is really important for us.”

Williams and the Bears will carry those lessons with them as they prepare for their season-opener against the Vikings on Monday night at Soldier Field. They’ll need all the help that they can get going against Vikings defensive coordinator Brian Flores’ aggressive defense.

Minnesota ended last season as one of the league’s top defenses because of its blitzing percentages. The Vikings blitzed a league-high 38.9% last season and had the fourth-most sacks with 49.

They had different threats doing it. Greenard finished tied for fifth in the NFL with 12 sacks last year, while linebacker Andrew Van Ginkel tied for eighth with 11.5.

Minnesota also added former Pro Bowler defensive end Jonathan Allen and defensive tackle Javon Hargrave in free agency this offseason to add more levels of pressure on opposing quarterbacks.

“The beauty of the defense, I said it yesterday – they create a lot of one-on-one matchups," Bears head coach Ben Johnson said. “When you have guys they feel good about winning their one-on-ones, it puts a lot of stress on our guys. I think we know the task at hand. We’ll see how practice goes here this week. It’s hard to have any breather plays this week. It’s just the nature of how [Flores] calls it. We gotta be locked in if we wanna have success against this defense.”

Williams had some success going against the Vikings last season. He threw for 340 yards and two touchdowns as he led the offense back from a 14-point deficit in the fourth quarter to force overtime. The results weren’t as strong in Minneapolis, where Williams threw for 191 yards and a touchdown in a 30-12 loss.

Although the Bears lost both matchups, Williams learned a lot going against Flores. Williams realized that Flores would blitz on every down and load the box to create those favorable one-on-one matchups.

He also learned the importance of adjusting.

Much like many offensive coordinators change up their play calls based on the defense they play, Flores does the same with his defense. Flores adds a “wrinkle” for each matchup to give the Vikings an advantage.

“Being able to adjust to those and be level-minded throughout the whole game is really important,” Williams said. “From there, once you adjust, it’s being able to go out there and execute. And even when things aren’t in our favor in maybe the first quarter, second quarter, whatever the case may be, and that sense of we haven’t adjusted fully yet is being able to still execute our base plays and get positive yards, positive gains, and keep us on the field and not have negative plays.”

Williams will also want to rely on his head coach’s experience going against Flores.

Johnson called offensive plays for the Detroit Lions against Flores and the Vikings over the past two seasons. The Lions won all four games and scored at least 30 points in each game.

“They got a bunch of good guys over there – [cornerback Byron Murphy Jr.], they obviously got the new guys on the [defensive line]. And then also [linebacker Jonathan Greenard], he’s a beast. Being able to maintain those guys and go out there and execute our gameplan and being able to go out there and be efficient with the ball is really important for us.”

—  Caleb Williams, Bears quarterback

But past success doesn’t guarantee future results. Johnson has emphasized the notion that his offense in Chicago will look different than it did in Detroit since the Bears hired him in January.

Williams repeated that belief Wednesday. While Johnson had success against Flores in Detroit, Williams and the Bears need to show what they learned Monday.

“We’ve got to go out there and prove it,” Williams said. “We’ve got to go out there and do it. That part of it was the Lions and Ben with the Lions, and we all have to prove it again, and we have to prove it as Bears, and he has to prove it again as a coach that we can go out there and put up as many points as possible on them.”