The New England Patriots reached the Super Bowl last season despite a shaky defense, but that unit could be drastically improved if Week 1 is any indication.
Tom Brady's offense, meanwhile, appears as potent as ever.
The Patriots aim for another impressive all-around showing Sunday in their home opener against the Arizona Cardinals, who seem likely to have Kevin Kolb under center after he led them to a come-from-behind win.
After coming within minutes of its fourth NFL championship with a defense that ranked 31st in the league during the regular season, New England may be even better built for a title this year after stocking up on talented rookie defenders in the draft.
The Patriots' two first-round picks quickly combined on a game-changing touchdown last Sunday, as Chandler Jones sacked Tennessee quarterback Jake Locker and forced a fumble that was scooped up and returned six yards for a touchdown by Dont'a Hightower.
"They have to do it again," defensive end Rob Ninkovich said of his young teammates. "That's the key."
Brady is leading one of the NFL's most formidable offenses again. He was 23 of 31 for 236 yards without an interception and threw touchdowns to star tight ends Rob Gronkowski and Aaron Hernandez, although the surprising star of the offense was Stevan Ridley.
The second-year running back rushed for a career-high 125 yards and a touchdown on 21 carries, equaling the number of 100-yard performances the Patriots had all of last year.
"We're talented, man, at every position," Ridley said. "We've got tight ends, we've got receivers. We've got one of the best quarterbacks, if not the best quarterback, an offensive line that's working hard and a group of young running backs that's trying to come in there every chance that we get."
The Patriots should have a good chance to go to 2-0 as they kick off their home schedule. They've won 24 of their last 25 in the regular season at Gillette Stadium, including a 47-7 win over Arizona in 2008 the last time these teams met.
Brady missed that game after tearing his ACL and has faced the Cardinals only once, but New England has won five straight in the series since Tom Tupa - a punter most of his career - threw three TD passes in Phoenix's 24-10 win in 1991.
The Cardinals have lost 13 of 15 on the road, but they won their sixth straight at home last Sunday, opening the season by beating Seattle 20-16.
John Skelton started at quarterback but injured his right ankle in the fourth quarter. Kolb replaced him and led Arizona on the majority of an 80-yard drive for the go-ahead touchdown, going 6 of 8 for 66 yards and the score to Andre Roberts.
Kolb struggled with injuries and ineffectiveness last season after the Cardinals acquired him from Philadelphia, losing six straight starts at one point. He also lost his competition with Skelton in the 2012 preseason, but he figures to draw another start Sunday unless Skelton makes an unexpectedly speedy recovery from a low ankle sprain.
Kolb said he's not thinking about winning back the starting job.
"The way my career's gone, the way that last year went, the way that it happened already this year, I'm not even worried about that," Kolb said. "I'm just going to play and let things take care of the way they're supposed to end up, so we'll see what happens."
Some of Arizona's fans even booed when Kolb entered the game last weekend, but Cardinals coach Ken Whisenhunt is hoping his strong performance is a turning point.
"I think he's got a lot of confidence now," Whisenhunt said, "which whenever you get into a situation like he's been through, when you have a good game like that and you make big plays for your team, it really does a lot for you."
Larry Fitzgerald had a relatively quiet opener, although two of his four catches came from Kolb during the key drive. He caught a 78-yard pass for Arizona's only touchdown four years ago in Foxborough.
Fitzgerald and Wes Welker were two of the top four in the NFL in receiving yards last season, but Welker had only three catches for 14 yards last Sunday.
"Every week is a little bit different," Brady said. "We have a lot of football to play and we're going to need everybody. There are going to be games where Wes has not as many opportunities and there are going to be games where he has a ton of opportunities."