TAMPA C oach Dirk Koetter walked to the back of the plane on the victorious Delta charter flight home after the Bucs' 31-24 win over the Falcons on Sunday night. The mood was light. Some players were laughing. Others were just goofing around. Not linebacker Kwon Alexander, who always has that look like the family dog needs to be put down. The second-year pro from Louisiana State had taken over the game with 17 tackles (15 solo), two for losses, two quarterback hits and a sack. But Alexander ignored the shenanigans and focused instead on a replay of the game on his Surface."I walked through the locker room pregame when some guys are stretching and some guys are seeing how cool they look in their uniform," Koetter said. "Kwon was watching tape on his Surface. So that's preparation and he's doing a good job with that."The NFL should prepare for this: Alexander and Lavonte David are budding superstars and on the verge of becoming the best tandem of linebackers in the league.In the new scheme under coordinator Mike Smith, Bucs defensive linemen are keeping the offensive linemen off their linebackers, so Alexander and David can bolt downhill with catlike quickness and pounce on ballcarriers before the double-team can reach them."The two linebackers to me are some of the most underrated players in the NFL," Falcons quarterback Matt Ryan said of Alexander and David on Sunday. "They're good players."The Bucs' front seven controlled the Falcons' offense, allowing only 2.4 yards per rushing attempt, a big reason why Atlanta converted only three of 13 third-down situations. Defensive linemen combined for six tackles, half of them by Gerald McCoy, who had a sack, two tackles for losses and batted down two passes.Meanwhile, Bucs linebackers had 28 stops, many on third down to kill drives."That's one thing that jumped out to me just going against them in practice and watching the tape," Koetter said. "Wow. There were some plays when both those two guys were flying downhill. That's one thing that's kind of become a little bit more in vogue with zone blocking. You're getting zone blocking schemes, you're trying to double the down linemen up to the linebacker. So what these defenses are trying to do, they run that linebacker down fast and take that double team off so now instead of a double-team to a linebacker, you've got two singles."Those two guys can really go."There was a time not long ago when linebackers struck fear into opponents. But they are no longer toothless like the Steelers' Jack Lambert or as physically intimidating as the Packers' Ray Nitschke. Today, players such as Alexander and David are rangy enough to drop deep into the secondary on passing downs."We all came out of the gate hard and had fun out there," Alexander said. "When you have fun, you can make great plays and everyone is going to be able to do their jobs and that's what's going to allow us to win."I started last Saturday preparing, putting everything in order. Like I said, preparation is a lot. When you're getting ready for a game, and you know what's going on, you're going to make a lot of tackles and a lot of plays so preparation is the key."David, a second round pick from Nebraska in 2012, is a cornerstone of the defense along with McCoy. He signed a five-year, $50.25 million contract before last season and already has a Pro Bowl and All-Pro selection on his resume.On Sunday, Alexander and David set the tone in the first series of the game. On first down, Alexander shot the gap and dropped running back Devonta Freeman for a 1-yard gain. Then on third and 9, fullback Patrick DiMarco circled out of the backfield and took a short pass before David used his speed and submarined him one yard short of the first down.A year ago, Alexander felt as if he let the Bucs down when he was suspended the final four games for using performance-enhancing drugs and the team lost all four games. Alexander said quarterback Jameis Winston helped him through some dark days. "He's always been there," Alexander said. "That's my brother and I'd go to war for him every day.'So Alexander rededicated himself and met with Smith every day at 6 a.m. during the offseason to learn the defense. "What's different is Kwon is not a rookie and he wants to take more ownership of the defense, which is great," Koetter said.And really, the plane ride isn't that important when you know you can fly.