As the Vikings prepare for Sunday's game with Houston at Reliant Stadium, we asked John McClain, who covers the Texans and the NFL for the Houston Chronicle, to give us his up-close-and-personal scouting report. Here are four things you need to know …

1) Without one of the top four quarterbacks in NFL history, you might not beat the Texans this season.

Through 14 games, Houston has stumbled just twice. In Week 14, New England's Tom Brady had no trouble handling Houston's blitzes, throwing for 296 yards and four touchdowns to ignite a 42-14 Patriots blowout. Eight weeks earlier, Green Bay's Aaron Rodgers lit the Texans up for 338 yards and six touchdown passes in a 42-24 Packers win.

Rodgers was nothing short of surgical in his dominance. Four of his TD tosses came against perfect coverage. Another came with a blitzer hitting him as he released the ball.

Both losses humbled Houston but did not cause panic.

"Those two losses weren't pretty," McClain said. "But when you take a step back, they ran into what I believe are two of the four greatest quarterbacks in history, both at the top of their games. I put Rodgers and Brady in that class along with Johnny Unitas and Joe Montana."

Needless to say, Vikings quarterback Christian Ponder isn't quite on that same list.

The Vikings will also be facing a Texans squad Sunday hungry to lock-up home field advantage throughout the playoffs, a goal the entire city has rallied behind.

"The road to the Super Bowl has never gone through Houston," McClain said. "Going back to the 'Luv Ya Blue' era with Bum Phillips, Earl Campbell, Elvin Bethea, they never had home field and lost two AFC Championship games in Pittsburgh with the feeling that if 'Well, had we played this game in the Astrodome we would have won.

"And then in the Run-and-Shoot Era with Jack Pardee, Warren Moon, Mike Munchak and Bruce Matthews in the late '80s and early '90s, they went to the playoffs every year. But they never had the home-field advantage."

McClain pauses.

"So two things we're hearing about every day this week are home-field advantage and Adrian Peterson."

2) Speaking of Peterson, the Texans may have the best chance of any defense this season to hold the Vikings star in check.

Houston ranks fifth in the NFL in rushing defense, allowing 93.2 yards per game. Obviously, the Texans have yet to face a back as explosive as Peterson. But having the ability to consistently lockdown against the run has been a big part of the team's success.

Only two backs this year have topped 100 yards against Houston. In Week 4, Chris Johnson went for 141 yards on 25 carries. Last weekend, Indianapolis rookie Vick Ballard rushed for 105 yards.

With Houston blowing Tennessee out, Johnson got big chunks of his yardage on draw plays late in the game. Ballard, meanwhile, had 60 of his yards on one series in the third quarter last Sunday.

Even with linebacker Brian Cushing being lost for the season in Week 5 with a torn ACL, the Texans have remained sturdy up the middle of their defense with nose tackle Shaun Cody and linebackers Bradie James and Darryl Sharpton playing well.

But …

"This is the game Cushing would have helped the most," McClain said. "He would have covered Peterson on pass routes. He would have been the guy between the tackles. This would be the time they'd really need Cushing to try to contain Peterson. Because overall, they're just in awe of him."

3) J.J. Watt is as good as advertised. Maybe even better.

Consider this. McClain has been covering professional football since the mid 1970s and he's certain he's never seen a more dominant season from a defensive player than the one Watt's having.

Pick whatever stat you'd like, it's bound to shed light on Watt's dominance. He has 19.5 sacks, 38 quarterback hits and 15 pass deflections. He has also forced three fumbles and recovered two. Plus, he's a beats against the run.

"Coupled with having the talent, he's very coachable," McClain said. "He takes coaching and has really learned. And then on top of that, he has that high motor. It just doesn't stop."

Five of Watt's deflections have led to interceptions with his combination of strength, effort and timing paying off.

"He's become very good at kind of pushing off and jumping," McClain said. "Not just leaping but pushing back a couple of steps and jumping. He's so quick about it that nobody's been able to stop it so far."

4) Receiver Andre Johnson is back on the top of his game.

Hamstring issues in both legs hindered Johnson in 2011. A groin issue slowed him some early this season.

Back in early October, following a four-game slump in which Johnson totaled nine catches for 164 yards, doubt began to creep in on whether his dominance had disappeared.

Yet since Week 6, Johnson has been back to his old self.

"Everybody was thinking, this guy turned 31, hit the wall and couldn't play anymore," McClain said. "But he didn't say very much, kept at it. And now he's on a rampage over the last nine games in which he's averaging 8.4 catches and 119.6 yards [per contest]."

Johnson's has 43 career games with at least 100 receiving yards and his 16 career games with at least 10 receptions and 100 yards are the most in NFL history, tied with New England's Wes Welker.