Mamas, don't let your babies grow up to be undersized defensive tackles.
Not if they want to have a future in the National Football League.
The 3-4 defense is back with a vengeance in 2009, spreading through the NFL like the flurry of Terrell Owens rejection notices.
Green Bay, Jacksonville, Denver and Kansas City all plan to use the 3-4 alignment extensively this fall, joining traditional 3-4 proponents like New England, Pittsburgh, Baltimore and San Diego.
"I think there's an awful lot of teams playing the 3-4 now, certainly compared to 2000, when I came to New England," Patriots coach Bill Belichick said. "You've probably got 8-10 teams basing out of the 3-4 defense. It's trendy, but that's the NFL. It's cyclical, and now the 3-4 seems to be as popular as it was in the '80s."
Given the success of the Patriots and the Steelers in this decade, it's not surprising the other 30 teams are busy playing follow the leader.
The key is to find a nose tackle sturdy and resilient enough to take on two blockers up front and complement him with dynamic edge-rushing linebackers like James Harrison and LaMarr Woodley of the Steelers.
That's not an easy combination to find, but the recent success of tweeners like DeMarcus Ware, Shawne Merriman and Terrell Suggs opened up new avenues for skilled players once considered too small for defensive end and too thick to drop back into pass coverage.
While the 3-man front is back in vogue, the pure Tampa 2 appears in full retreat.
The main architects, Tony Dungy and Monte Kiffin, will not be on the NFL sidelines next season. Former Buc assistants Rod Marinelli and Herm Edwards have been dismissed as head coaches.
Todd Haley, Edwards' successor in Kansas City, appears committed to shifting the Chiefs to a 3-4 base defense.
That's logical because Haley's new boss, GM Scott Pioli, was Belichick's primary talent evaluator in New England and he's well aware of the advantages of a 3-4 alignment done right.
New Bucs defensive coordinator Jim Bates has an extensive background in the traditional 4-3 and the Bucs don't have the personnel right now to thrive in a 3-4 format, even if head coach Raheem Morris was ready to return the franchise to its defensive roots under inaugural coach John McKay.
Although all four NFC South clubs are expected to retain a 4-3 alignment, the rest of the league is changing quickly.
Six of Tampa Bay's 10 opponents outside the division this fall are expected to feature a base 3-4 defense, forcing significant changes in the Bucs' blocking scheme.
The Steelers have won two of the past four Super Bowls and Dick LeBeau's intricate zone blitz package out of the 3-4 is forcing teams to scramble in an effort to keep up. It's a copycat league - and Pittsburgh has every defensive coordinator from Denver to Jacksonville looking out for No. 1.