Now would be a really good time for Vikings fans to put their knuckles to the nearest piece of wood.

Your team is 4-1 and remarkably healthy by mid-October NFL standards.

In fact, the Vikings' biggest injury concern of the season just resulted in Jerome Simpson, a receiver with four catches, having to sit out Wednesday's practice for what coach Leslie Frazier called precautionary reasons. On the scale of NFL injury scares, this was the equivalent of a 3-year-old in a Hello Kitty costume yelling, "Boo!"

The scare began Sunday morning when Simpson, with no prior warning signs whatsoever, woke up with weakness and numbness in his lower left leg. He couldn't push off and didn't catch any of the three passes thrown his way during a 30-7 win over Tennessee later that day.

On Monday, a magnetic resonance imaging (MRI) exam revealed a back issue as the cause of the ailment. The scare advanced to Level 2.

Wednesday, Frazier tamped down all speculative long-term ramifications by saying Simpson was doing much better, doesn't need surgery and would miss Wednesday's practice "just to give him another day of rest and recuperation."

Frazier expects Simpson to return to practice Thursday or Friday and added that, "All indications are there is a very good chance" he will play on Sunday at Washington.

"We'll know more as he responds to some of the treatment that [head athletic trainer Eric Sugarman] will give him," Frazier said. "We don't think it's anything long-term at all."

Visual proof of the Tigger-like spring returning to Simpson's step also was supplied Wednesday when he was spotted in the locker room leaping over two large laundry bins in a single bound. Later, with much slower reporters waiting for him after practice, Simpson recorded one of the faster 30-yard dashes to a side door in franchise history.

"It sounds like he's heading in the right direction," Frazier said. "And we can clearly say that's behind him."

Meanwhile, teams around the league would love to have this as their biggest injury scare. Not to mention the fact the Vikings have had just two starters (linebacker Erin Henderson and safety Mistral Raymond) miss a total of four games this season.

In Houston, the 5-0 Texans have placed linebacker and defensive leader Brian Cushing (knee) on injured reserve (IR). In Baltimore, the Ravens have reached 4-1 without reigning NFL Defensive Player of the Year Terrell Suggs (Achilles).

In Washington, the Redskins put linebacker Brian Orakpo (pectoral) and defensive end Adam Carriker (quadriceps) on IR after Week 2. In New York, the Jets have lost cornerback Darrelle Revis (knee) and receiver Santonio Holmes (foot) for the season.

And in Green Bay, the Packers have been dealing with their usual injury issues since linebacker Desmond Bishop went down for the year with a hamstring injury in the first preseason game. Running back James Starks (toe) hasn't played, running back Cedric Benson (foot) is out at least eight weeks and receiver Greg Jennings (groin) will miss his second consecutive game this week.

Meanwhile, back at Winter Park, the Vikings have shocked the league while Simpson's impact as their long-absent deep threat has been limited to three big plays in one game. After his three-game suspension and before his leg issues, Simpson went to Detroit and forced two deep pass interference penalties and made a leaping catch over a defender for a key 27-yard gain late in the game.

"Even when you have good coverage, like [Detroit] did with that last 27-yarder he caught, his athletic ability sometimes overrides good coverage," Frazier said. "You need a guy like that."

That skill of Simpson's may become even more valuable down the road as defenses start crowding the line of scrimmage to stop the bubble screens to Percy Harvin. Then again, the team has made it this far.

"We want him back on the field," quarterback Christian Ponder said. "But we got a lot of depth at the receiver position. Having the veteran guys like Michael Jenkins and Devin Aromashodu and Stephen Burton has really stepped in.

"They're doing a great job, and obviously Jerome is going to be even better when we put him on the field. But we're winning without him and we've shown we have all the right pieces, even though we definitely want him back on the field."