Week 5 three-and-out

The Vikings are 3-1 and getting big plays in all three phases. Now they head into a Week 5 home game against an inferior opponent with an injured starting quarterback and a shaky defense. But wait, there's more. Here's a trio of other things you should know in this edition of Three and Out.

1. Chris Johnson's struggles through the first three weeks of the season were something of a chicken-and-egg scenario.

The Titans running back rushed for only 45 yards on 33 carries in the first three games, a putrid average of 1.4 yards per attempt. Then on Sunday in Houston, against a vaunted Texans defense, Johnson blew up for 141 yards on 25 carries.

Go figure.

Johnson only carried the ball an average of 11 times through the first three games, in part because the Titans fell behind big early against New England (21-3 at halftime) and San Diego (14-0 in the first quarter) and opted for a pass-first attack against a vulnerable Detroit secondary.

But those big early deficits were also partially a byproduct of Tennessee's inability to get its ground game established.

So now what? The Vikings defense has held the top back of their first four opponents to an average of 52 rushing yards per game. Yet they know Johnson remains dangerous. Last weekend's eruption in Houston offered a timely reminder.

Johnson's biggest season came in 2009 when he amassed 2,006 rushing yards, which later gave him leverage in negotiating a four-year contract extension worth $53.5 million.

Yet in his 20 games since getting that deal, Johnson has averaged just 62 yards per contest and 3.9 yards per carry. Is that downward trend worrisome?

Explained Titans coach Mike Munchak: "Last year was the first time we kind of stubbed our toe on it a little bit. ... The way he started, it came so easy the first three years. People didn't expect those kinds of numbers from him when he first came into the league. And then he goes for 2,000 and expectations just got large. We still feel like he's a back where 1,400-1,500 [yards] is where he should be."

2. Leslie Frazier doesn't want his team's sensational September to be this season's high point.

The view from the top of the NFC North has certainly been invigorating. Now we'll see how this surprising squad handles its early success throughout October. Three home games await this month and there's a belief that the second quarter of the season will be telling.

Earlier this week, Frazier reminded his players of all the things they've done well to reach this point. Most notably, he highlighted the attention to detail the team has shown in its preparation each week.

And yes, there was the obligatory reminder that a 3-1 record does not guarantee long-term relevance.

"All of us have been around long enough to know that there are no champagne bottles being popped in September," Frazier said.

3. The Titans were thoroughly impressed with Christian Ponder during the predraft process in 2011.

With the eighth pick in that draft, Tennessee plucked Jake Locker to be their quarterback of the future. Four picks later, with Locker off the board, the Vikings reeled in Ponder. But don't underestimate just how close those two picks were to being reversed.

That said, Munchak hasn't been surprised at all by how well Ponder has played early in his second season.