It’s now or never for the Houston Texans. Either they win the AFC South this season or spend the rest of their miserable existence in NFL purgatory.

All right, so that was a little extreme. But you’d have to be a corpse not to feel the sense of urgency that is surrounding the Texans as we draw closer to the 2011 regular season.

Peyton Manning’s neck injury has cast a cloud of doubt around the Colts. Tony Dungy was probably right when he recently said that unless Manning is dead, he won’t miss Week 1. But even if he does suit up, Manning, or Mr. Preparation as his poker buddies call him, hasn’t done much prepping for the 2011 season. How effective will he be early on? Will this be an injury that nags him the entire season? Will he be Peyton Manning? Because if he isn’t, then it’s fair to say that the Colts are a rather average team.

Nevermind that though; the Texans can’t be worried about what Manning and the Colts are doing. They need to focus on themselves because their moment to shine is here. Besides re-signing running back Arian Foster and tight end Owen Daniels to keep their explosive offense intact, the biggest move Houston made this offseason was hiring Wade Phillips to be its new defensive coordinator. Say what you will about Phillips’ inability to be a head coach, but the man knows how to run a defense. And he knows something about quick turnarounds, too.

The last seven times that Phillips has taken over as a head coach or defensive coordinator, his new team has reached the playoffs in its first season. And only once in those seven years has Phillips taken over a club that was coming off a winning record, which is a testament to the impact he can have on new teams. That’s a good sign for Houston, which finished 6-10 last year largely because of a defense that finished third to last in yards allowed and fourth to last in points per game.

The Texans also signed a key piece this offseason to help Phillips turn around the team’s defensive misfortunes. While they heavily pursued corner Nnamdi Asomugha in free agency, the Texans did well to land the second-best DB on the market in Jonathan Joseph. Still in his prime at 27, Joseph flashed shutdown corner ability in Cincinnati and should dramatically improve the league’s worst secondary from a year ago.

Of course, the defense wasn’t the only problem last year. The Texans have been a team that has struggled against divisional opponents the last two years. After going 1-5 in 2009, the Texans did finish 3-3 against the AFC South last season, but 3-3 usually doesn’t win divisional crowns. In fact, the 2010 Kansas City Chiefs have been the only team in the last four years to win their division despite having a losing record, which shines light on how important it is that the Texans take care of business against Indy, Jacksonville and Tennessee this year.

I joked earlier about this season being a “now or never” opportunity for the Texans to win the AFC South. Unless owner Bob McNair abruptly folds the franchise after this year, the Texans may be favored to win in 2012 or beyond. That said, when are the Texans going to have a better opportunity than now? Phillips was the right man for the defensive job, Manning’s injury leaves a lot of uncertainty in Indy, and Jacksonville and Tennessee are largely devoid of talent.

Now or never? Not quite. But then again it might as well be.