It's not that Allen, who was acquired through a pre-draft trade with Kansas City, is the final component for a team looking to reach the postseason for the first time in three years. It's that he's a reminder that the Vikings are indeed heading in the right direction.
"Good players like to see more good players join their team," Childress said during a recent interview. "And nobody is more excited [about Allen] than guys like [cornerback] Antoine Winfield and [free safety] Darren Sharper. They can really see what we're building here."
The Vikings actually have every right to be thrilled about Allen. Though some skeptics think Minnesota gave up too much to get him -- the Vikings dealt a first-round pick and two third-round selections in this year's draft to Kansas City -- they will benefit greatly from this deal. Allen has gone from being a talented defensive end with a checkered past to a rising star who's grown up just as he's hitting his prime. By adding the 26-year-old to an already sturdy front seven, the Vikings made the kind of move that could immediately change their fortunes.
For one thing, Allen is coming off his first Pro Bowl season, a year that was even more special because he overcame the taint of two DUI convictions by leading the league with 15.5 sacks, also a career high, in 2007. He's also more motivated than ever to deliver on the six-year, $74 million the Vikings gave him, a deal that made him the highest-paid defender in league history.
"It's a huge relief to be here," said Allen, who had been tagged as a franchise free agent in Kansas City when the offseason began. "I didn't have to sit out the year or wait to see how things turned out [with the Chiefs]. Now I can just go out and play football with a good organization, which is all I really want to do."
It's no secret what the 6-6, 270-pound Allen brings to a Vikings defense that was great against the run (it ranked first in the NFL in rush defense) and lousy against the pass (it ranked last in that category) last season. After failing to find a stud pass-rusher through the draft the past few years, the Vikings landed a player who knows how to get after quarterbacks. After all, Allen accumulated 43 sacks during his four seasons in Kansas City. What's more impressive is that he didn't really develop an assortment of pass-rushing moves until last offseason.
Now Allen can beat opposing linemen with his relentless motor and his technical skills. He's also just as hard to handle when teams attack him on the ground.
"People focus just on his sack totals, but we're not talking about a guy who can't play the run," Childress said. "Jared is just as aggressive against the run as he is against the pass. You really can't put a price tag on the way he plays the game. His energy is infectious."
Childress also believes that Allen has joined the Vikings at exactly the right time in the player's brief career. Allen has worked hard to overcome the headlines he created with those two DUI convictions, and he impressed Childress with his candor when they met prior to the trade. Childress had done his due diligence -- he had interviewed several people in Allen's background -- but Allen's sincerity helped convince the coach.
"He asked me the same questions that everybody else has asked me," Allen said. "I just told him the truth and he obviously liked what he heard."
The next step for Allen is getting off to a good start with the Vikings. He's already developed a comfort level in his new city, as he's found a home in Minneapolis along with two boats to keep on one of the nearby lakes. Allen also has more peace of mind these days. Vikings guard Steve Hutchinson dined with Allen a few nights before the trade was finalized and he could sense Allen's desire to get out of Kansas City and move on with his life. As far as Allen was concerned, so many bridges had been burned between himself and Chiefs general manager Carl Peterson that there was no way Allen could enjoy another year with that franchise.
Most importantly, Allen has reached a point where he clearly understands how valuable football is to him, that it's something he will not jeopardize again. As former Chiefs linebacker and current Miami Dolphin Boomer Grigsby said: "Jared was always a very good player before all the things he went through but now he has even more reasons to strive to get better. You're talking about a guy who went from being a 10.5-sack guy to a 15.5-sack guy in one season -- and that's with only 14 games last year. [Allen missed the first two games while serving a suspension for violating the league's alcohol and substance abuse policy.] He's a rare breed."
The Vikings are banking on Allen continuing that same improvement this coming season. He's always claimed that he's at his best with his back against the wall and he's spent the past two years proving exactly that. Now he has the chance to show what he can do with an entire league expecting greatness from him. So far, the odds are good that he'll find a way to live up to that challenge as well.
Jeffri Chadiha covers the NFL for ESPN.com