It didn’t even take Khalil Mack one full half of football to confirm to everyone that he’s worth every penny of that six-year, $141 million contract the Bears gave him after sending two first-round picks in a package to the Raiders just more than a week ago.

Anyone watching the Bears' season opener against the Packers on Sunday night understood why Chicago willingly met Mack’s demands to guarantee $90 million in said deal (a record for defensive players).

The sack, quarterback pressures, forced fumble and recovery, and interception returned for a touchdown all served as evidence. So too did Mack’s impact as he disrupted the pocket and then set up teammate Roy Robertson-Harris for the hit that sent Aaron Rodgers to the locker room for examination of a knee injury.

Mack nearly single-handedly changed the complexion of the game and the Packers’ season.

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Rodgers, of course, pulled off his own Willis Reed moment and led Green Bay to an astonishing second-half comeback in a 24-23 win. But there’s no denying the impact Mack can and will have for the Bears. Chicago had the NFL’s 10th-ranked defense last season, but the addition of an elite pass rusher should launch the unit even higher.

He makes everyone around him better because of the attention he commands.

Remarkably, Mack was largely playing off of his instincts and natural ability given his limited time in defensive coordinator Vic Fangio's scheme. He also is still rounding his way into top shape after training on his own all summer while he waged a holdout with the Raiders.

His impact by the midway point of the season could be scary, with Jon Gruden likely to face questions about the trade again and again.

But the magnitude of his decision won't be clear for some time. The popular school of thought is that Gruden had better draft a pair of Hall of Famers with those two first rounders. But in reality, he doesn’t have to. With a 10-year, $100 million contract, Gruden has the security to make long-term decisions like this.

It’s possible that the move could benefit both teams. The Raiders could now have the building blocks to fortify the franchise's future, while the Bears now possess the difference-maker needed to support rapidly improving quarterback Mitchell Trubisky and transform this team into a legitimate contender.

Allen time in Buffalo

Despite a woeful performance from quarterback Nathan Peterman in the season opener, Bills coach Sean McDermott said he needs to look at the tape again to determine what direction Buffalo should go at quarterback.

McDermott should save himself some time by making the switch to rookie Josh Allen right now.

Peterman on Sunday posted a 0.0 quarterback rating while completing just five of 18 pass attempts for 24 yards and two interceptions in Buffalo’s 47-3 shellacking by the Ravens. The score was 40-0 when McDermott yanked Peterman for Allen on Sunday.

Swapping out Peterman after just one week isn't an overreaction. This performance featured many of the same struggles that plagued the second-year passer in his only other career start (last season) – a five-interception debacle against the Chargers. Once again, he held onto the ball too long. He continues to lack proper awareness and struggles with his decision-making. He just doesn’t appear to have what it takes.

The Bills’ choice to roll with Peterman entering the season raised eyebrows, especially after the team traded AJ McCarron to the Raiders just months after signing him in free agency. Team brass felt like Peterman gave them a better chance to win now, and afforded Allen more time to develop. But it’s unclear why McDermott had so much confidence in Peterman that he believed the Bills wouldn’t benefit from a veteran presence as an insurance policy.

Now, however, the Bills seemingly have no other choice if they want to be competitive this season but to switch to Allen, even if he’s developmentally premature.

You have to feel for the veterans on this team, which ended league's longest active playoff drought last season under the direction of Tyrod Taylor, whom Buffalo traded to Cleveland. Now, however, the Bills appear to be in full rebuild mode. True professionals have pride, so it's unlikely they will quit this early in the season. But it’s tough to deal with a lack of a competitive presence at the most important position on the field. The pressure can get to players in these situations because they feel like there’s no margin for error thanks to the shortcomings they have to offset at quarterback.

McDermott and his assistants have a very hard task ahead of them, but they made it harder on themselves because of their lack of foresight in managing the passing attack.

A few other things I’m wondering …

What happened to the Saints’ defense? Vegas had New Orleans picked as 9 1/2-point favorites against the Buccaneers, but Ryan Fitzpatrick lit them up for 417 yards and four touchdowns in a 48-40 victory. That just can’t happen, not for a team that some consider Super Bowl contenders.

Will Fitzmagic have staying power? Now the question for Tampa Bay is if that game was an aberration or if Fitzpatrick can play well enough for the Bucs to stick with him even after Jameis Winston returns in Week 4 from his suspension. Coach Dirk Koetter has played it safe thus far and is noncommittal. But the pressure to make a call could mount.

Does Adrian Peterson still have it? He certainly looked like it in his Redskins debut as he rushed 96 yards and a touchdown (the 100th of his career) and passed Jim Brown for 10th on the all-time yardage list. It's fair to wonder if Peterson can maintain this level of production or if he’ll wear down as the season goes on. But he’s off to a great start.

Follow Mike Jones on Twitter @ByMikeJones.