Chicago Bears outside linebacker Khalil Mack encapsulated last season in four simple words: "I wasn't good enough."

Mack's 45 tackles, 8.5 sacks and five forced fumbles would constitute a decent year for your average defender. But Mack is not an average defender -- both in terms of past production and his salary.

A former NFL Defensive Player of the Year, Mack had stretches of such dominance in 2018 (his first season in Chicago after a trade from the Raiders) that expectations reached almost unimaginable heights in the buildup to 2019.

Moreover, factor in the money. The Bears signed the five-time Pro Bowler to a massive six-year extension that included $90 million in guarantees. Mack earned $41 million in salary in 2018 and $15.5 million last year.

The results: Mack, 29, was good, not great. As Chicago's season sunk in October, Mack registered just one sack during the team's backbreaking four-game losing streak to the Raiders, Saints, Chargers and Eagles. The Bears never recovered. Chicago finished 8-8 and missed the playoffs for the eighth time in nine seasons.

"Wasn't good enough at all," Mack said. "Understanding that, there are different intangibles that came with it. I don't make any excuses. I just rise to the occasion, and I am getting ready for this one. It's going to be a fun one, man. I can't wait.

"... It was a lot of factors, man. Playing this game, you deal with all types of stuff, and I’m not one to make excuses. But I am going to make sure I am out there with my brothers, giving it my all every week, and that's what you all saw. So not to get into details, but, man, we’re ready this year. We're ready. We’re ready for it all."

Chicago was desperate to add another legitimate pass-rusher opposite Mack after the defense tied for 24th in sacks and 22nd in pass-rush win rate, per ESPN Stats & Information. The Bears signed veteran Robert Quinn in free agency for $30 million guaranteed and released former starting outside linebacker Leonard Floyd.

Quinn had the highest pass-rush win rate (32.2%) in the league last season as a member of the Dallas Cowboys. He also tied for ninth in sacks (11.5) and fourth in tackles for loss of five yards or more (14).

Conversely, Floyd -- the ninth pick of the 2016 NFL draft -- had three sacks, no forced fumbles and a 12.4% pass-rush win rate, which was 57th in the NFL.

Quinn has started slowly in Chicago. The Bears kept the 30-year-old veteran out of team drills the first week of padded practices because -- per the team -- he dealt with a recent personal issue and required extra ramp-up time.

Still, the Bears are optimistic Quinn's game-day presence will alleviate some pressure on Mack, Bears coach Matt Nagy said.

"Everyone always goes to the numbers with really all players," Nagy said. "When you have a lot of sacks in your career like [Mack] does, that's what people evaluate off of. But I can tell you firsthand, from going against Khalil and other great pass-rushers, we look for the sacks, but we also look to see how much are you affecting the quarterback. Every team that we play is going to have to game-plan for him.

"The only thing that matters is, is Khalil ready to rock and roll? And he certainly is. Just from the talks and discussions, he's had an unbelievable offseason. He's very, very focused. He's not a guy that says a whole lot, which you like, you appreciate. He does his speaking on Sundays, on game day."

Pro Bowl safety Eddie Jackson echoed the head coach's sentiments.

"Mack is going to be Mack," Jackson said. "That's just him. Nothing's changed, honestly. He's still going to go out there and be that type of competitor you see day in, day out ... just being a big brother to us, to the younger guys, giving us a shoulder to lean if we need it, a helping hand if we need it. ... He's going to always be that stand-up guy. No slacking. Everything is just up."