On April 24, a day after signing free agent Jerome Simpson, Vikings General Manager Rick Spielman beamed about the receiver's speed and athleticism, lauding Simpson as "a genetic-type freak."

Certainly, at that time, Spielman figured Simpson would roll into mid-December with more than 15 catches and 176 yards.

In early June, after the Vikings had augmented their receiving depth through the draft, offensive coordinator Bill Musgrave assessed the skills of rookie Greg Childs and saw a guy who could become a match-up headache.

"He's got the speed to get down the field," Musgrave said. "But he also has the size to muscle little DBs at the same time."

Certainly, Musgrave had no way of knowing Childs would rupture the patella tendons in both knees during training camp, killing his 2012 season.

And in early August, as a crowded position battle was unfolding in Mankato, receivers coach George Stewart noted how Devin Aromashodu had stepped forward, saying that the seventh-year veteran was "still ascending."

"We've talked to him about making those great moment-of-truth plays down the field," Stewart said. "What those are is that ball is in the air, the fans are out of their seats, 'Is he going to catch it? Is he not?' It's the moment of truth."

Yet in a moment of truth last Sunday, Aromashodu couldn't haul in a 45-yard touchdown pass, continuing a disappointing eight-game stretch in which he has had only two catches for 44 yards.

It's been a struggle all season for the Vikings to ignite their deep passing attack. For myriad reasons, the solutions they thought they had haven't worked out. Now, they will enter the final three games trying to steal a playoff berth with an offense that has been one-dimensional.

A long story short

The Vikings travel to St. Louis this weekend with the NFL's worst passing offense, averaging only 172.6 yards per game.

Since the season's midpoint, the numbers are even more abysmal, with the Vikings averaging 120 passing yards and their wide receivers combining to contribute seven catches for 70 yards per contest.

With Percy Harvin now on injured reserve, the Vikings will likely suit up five receivers on Sunday -- Simpson, Aromashodu, Michael Jenkins, Jarius Wright and Stephen Burton -- who have 75 catches, 887 yards and three TDs for the season. Combined.

For perspective, nine NFL receivers have topped those totals.

Even as opponents continue to march eight and nine defenders toward the line, often using only one deep safety and daring the Vikings to test them long, the success down the field has not come.

Christian Ponder's longest completion against Chicago last weekend was a 16-yarder to Wright after the rookie went in motion into the backfield and then caught a flare at the line of scrimmage.

A week earlier at Green Bay, Ponder's longest connection to a receiver covered 18 yards -- to Simpson, in the final 3 minutes with the Packers using loose coverage.

Health problems

And so the chicken-and-egg debate continues. Are most of the passing struggles attributable to Ponder's inconsistency? Or is his slump greatly affected by not having enough dynamic receivers?

The injury bug has bit that receiving unit. It's not just losing Harvin the final seven games with a sprained ankle. Simpson has battled a back issue since October. His season totals: 15 grabs, 176 yards.

"You can't get around the injury," Vikings coach Leslie Frazier said Thursday. "It's definitely had an effect on his play. So we're doing the best we can."

Frazier seems resigned to the idea that Simpson will not be at full force this season and is instead asking the receiver to "give us whatever he can."

It has been clear to Frazier that Simpson's speed has lessened and that he is having difficulty cutting.

"Coming out of his breaks," Frazier said, "you can see he's not as crisp as he was before that injury."

On the run

So Frazier is seeing not only the run-first offense he always wanted but an attack that may need to adopt a run-first, run-second, run-third, pass-only-when-necessary philosophy.

That strategy worked against the Bears on Sunday. Adrian Peterson carried the ball on 12 of the Vikings' 15 first-quarter plays, racked up 104 yards and provided a 14-0 lead.

Peterson finished with 31 carries, the most he has ever had.

For obvious reasons, Frazier said he is not closely monitoring Peterson's workload, eager to ride the All-Pro back as much as possible.

Asked if there was a carry total he would identify as too much, Frazier grinned.

"Probably not," he said.

The passing situation being what it is, it's a logical answer.