LAKE FOREST, Ill. — Chicago Bears coach Marc Trestman looked around the field Monday night during his team’s 27-19 victory over the New York Jets and saw nothing but inexperience.

At one cornerback spot was rookie Kyle Fuller. Up front, he had rookies Will Sutton and Ego Ferguson playing tackle, and at strong-side linebacker was second-year player Jonathan Bostic, previously a nickel linebacker or middle linebacker. At safety he had rookies Brock Vereen and Ahmad Dixon.

Ahmad Dixon?

“We went through this whole training camp saying we were going to rotate guys around, that we had a plan, that we were going to work all these guys and get them in, and then (Ahmad) Dixon’s out there, and he’s been here for about three days,” Trestman said. “He’s out there playing right at the ultimate moments of the game.”

Fortifying the Bears’ depth was a goal of general manager Phil Emery since the end of last season when the defense caved in beneath the crush of numerous injuries. He just didn’t anticipate needing it so soon.

The coaching staff’s commitment to rotating in reserve players with starters at camp apparently made a difference because the rookies and other inexperienced backups came up with enough plays to hold the Jets to one touchdown and four field goals in six trips to the red zone.

Safeties Chris Conte (shoulder) and Ryan Mundy (stinger) left with injuries, and safety Danny McCray was shaken up for a few plays, creating the need for even Dixon to play after he was signed two weeks ago off the Minnesota Vikings’ practice squad.

Fuller already was starting due to the season-ending pectoral injury to Charles Tillman. The concussion Jeremiah Ratliff sustained last week created the need for Ferguson and Sutton to play more, and Bostic played because Shea McClellin broke his hand during the week in practice.

“It’s just a credit to (defensive coordinator) Mel (Tucker) and our staff,” Trestman said. “You look out there, and we’re playing with Will (Sutton), we’re playing with Ego (Ferguson), we’re playing with Kyle (Fuller), and we’re playing with Brock Vereen on ‘Monday Night Football’ three games into September.

“As I said, our coaches have done a very good job of getting them ready, and our veteran players have certainly been a part of that preparation, teaching them what it takes to play in this league. And there’s no better way to learn than at 11 o’clock at night on Monday night. Sometimes that’s where you get your best learning in.”

Fuller made his third interception of the season, a key grab in the end zone, and forced two fumbles that the Bears failed to recover. Bostic made a team-high 13 tackles and deflected two passes, including one dropped interception that could have essentially ended the game with two minutes remaining.

Third defensive end Willie Young produced his career-high fourth sack, and McCray, acquired largely for special teams, made nine tackles in the secondary.

Ferguson got his first career sack, and Vereen successfully thwarted the final pass at the back of the end zone to secure the win.

The Bears’ defense is tied for the league lead in turnovers forced (eight). On Monday, the unit enjoyed its best game against the run (114 yards) despite playing largely with a patchwork lineup — a direct contrast to last year when the run defense caved in due to injuries.

“(Injuries) can’t be an excuse for us,” Bostic said. “This guy is down, this guy is down. It’s got to be next man up. No matter who it is, there can’t be any drop-off.”

The depth situation carries over to offense, as well.

With wide receiver Brandon Marshall going out at times due to a leg injury and ankle sprain, and two starting offensive linemen already out, the offense dug deep for various ways to move the ball. Backup center Brian de la Puente and guard Michael Ola haven’t been able to do much against two stout defenses in terms of run blocking, but they have given quarterback Jay Cutler enough time to find targets.

The positive aspect of all the Bears’ injuries so far is that only Tillman’s was a season-ender, although Conte’s situation is potentially a serious one because he had offseason shoulder surgery and did not begin practicing until the start of preseason games.

“You just can’t panic,” linebacker Lance Briggs said. “Don’t panic. In situations like that, the next guy comes in and you’ve just got to read your keys and play ball.

“All of us are on this team for a reason.”

Last year, it wasn’t clear the backups knew those reasons. It is obvious so far the message is being successfully communicated this season.

REPORT CARD VS. JETS

PASSING OFFENSE: A-minus — Armed only with the pass as a weapon, and with the line trying to block blitzes almost every play, QB Jay Cutler still managed to avoid the big interception. He did fumble once on a play officials blew that could have been a game-turning touchdown return. Even with WB Brandon Marshall held to one catch, the passing game worked.

RUSHING OFFENSE: C — Although they ran for a scant 60 yards and a 2.9-yard average, the Bears were able to run in the fourth quarter on a big drive against one of the league’s best run defenses to kill time en route to a 45-yard Robbie Gould field goal. Three times Forte ran for first downs on third-and-short, a situation the Bears often left him off the field for in the past.

PASS DEFENSE: B-plus — The total yardage figure of 316 looks bad, but with Fuller’s interception, one by S Ryan Mundy for a pick-six and a steady pass rush, the Bears were able to hold QB Geno Smith to a 71.5 passer rating and an outstanding 4.7 yards per pass attempt. The rush added three sacks and forced Smith to try to throw from the pocket.

RUSH DEFENSE: A-minus — New York’s 114 yards included no runs longer than 17 yards — and the Jets possess one of the league’s best running attacks. The Bears effectively stopped the read-option for the second consecutive week, and DE Jared Allen’s willingness to sacrifice his outside pass rush to maintain the integrity of the scheme is a big reason. Only once in the previous 13 games had Chicago held a team to fewer rushing yards, and that was against a weak Cleveland running attack. The Bears did it Monday without possibly their best run defender on the line, DT Jeremiah Ratliff.

SPECIAL TEAMS: B-minus — Although the Jets had the 31-yard line as an average starting point to 23 by the Bears, this was by far Chicago’s most consistent performance on special teams. PK Robbie Gould moved around his kickoffs, and the punt coverage team recovered a fumble that led to a touchdown. A few penalties and a near blocked punt made it less than a perfect night, and the kick return problems were solved only by downing every kick in the end zone to at least give the offense the 20 for a starting point.

COACHING: A — Defensive coordinator Mel Tucker’s ability to get all the reserves up on a game plan to stop the run and read-option was possibly his best effort since the 2013 victory over Pittsburgh. Head coach Marc Trestman blended in just the right commitment to the run. The Bears ran sparingly and didn’t force the issue. The passing game became a game of chess between Trestman and Rex Ryan, with his blitzes, and Trestman won.