This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

CHICAGO – Even in the rich history of the Chicago Bears, you’d be hard pressed to find a better debut month than the one their outside linebacker had in September.

Khalil Mack has been that good since coming over to the team in a trade from Oakland – and the NFL recognized that Thursday.

After four impactful games to start his Bears’ career, the linebacker was named the NFC’s Defensive Player of the Month for September. This comes after he collected five sacks – second-highest in the NFL – and forced a league-high four fumbles along with the Texans’ JJ Watt in the first four games of his career with the Bears.

On top of that, he also had an interception return for a touchdown in the second quarter of the Bears’ Week 1 game against the Packers. Mack has collected 17 tackles on the season.

Seeing the 2016 AFC Defensive Player of the Year on the field for the Bears might still seem a bit surreal for Bears fans considering that he wasn’t even on the radar late in the preseason. Eight days before the opening game, general manager Ryan Pace stunned many with the acquisition of Mack in exchange for two first round picks.

Fans saw his impact in the opening game as he single-handedly took over the first half with an interception, sack, and forced fumble against the Packers. That pressure from the outside didn’t cease in the next three games, as Mack became the first since the Colts’ Robert Mathis in 2005 to have four consecutive games with strip sack.

His influence has caused a ripple effect in the Bears’ defense that struggled the previous three years under Vic Fangio to force turnovers. They currently lead the league in forced fumbles with eight and also have the same amount of interceptions, which equals the amount the Bears had in each of the previous three years.

All of these have helped the unit rank fourth in total defense in the NFL (294.5 yards per game) and third in points allowed (16.3), which have been critical in the team’s 3-1 start to the season. While Mack has been a catalyst for the improvement, he’s tried to put the spotlight on his teammates as well.

“We’re getting better every week. It’s not just about me,” said Mack after the Bears’ 48-10 win over the Buccaneers. “You see the guys on the back end making plays and that’s what you want to see. It’s a good feeling, especially going into the bye.”

Mack has a lot to do with those good vibes – and the rest of the NFL is taking notice.