Tom Brady walked off the field under his own power. Several teammates didn't think he was hurt badly when he grabbed his left knee after being knocked down.

Tebowmania is in full rage again.

Tom Brady’s knee injury has awakened the sleepy masses of true believers, who see this as an opportunity for Timmy to step in and lead the New England Patriots to another Super Bowl.

Sure, call Mickey Mouse right now and let’s book a parade for Disney World!

Tampa Bay Times reporter Rick Stroud talks about quarterback Tim Tebow at the New England Patriots training camp after a joint practice with the Tampa Bay Buccaneers on Tuesday, August 13, 2013.

Um, not so fast.

A few things we should file under “reality check:”

Brady’s injury isn’t that serious. He is day-to-day, after he was hit throwing a pass during a joint practice with the Tampa Bay Buccaneers, but the injury doesn’t seem to be something of great concern.

ESPN.com, citing a source, reported that an MRI on Brady's knee was negative and that he is considered day-to-day with a knee sprain.

Second, Ryan Mallett, not Tebow, is New England’s backup quarterback.

Third, let’s remember that Tebow’s contract is not guaranteed and he could very well get cut by the time the exhibition season ends. If the Patriots keep three quarterbacks, they would have to give up a roster spot that would be more valuable with a special teams player.

Once again, let’s rinse and repeat:

Personally, I wish all good things for Tebow. But the fact is that the vast majority of NFL coaches have not deemed him fit to be a viable starting quarterback. The fact that Tebow went just 4-for-12 in the game for 55 passing yards in the first preseason game against Philadelphia did him no favors trying to change that perception.

The fact that he also ran the ball four times for 31 yards gives a hint of his greatest asset -- the ability to run and improvise.

But you can’t run an improvisational offense in the NFL. You need to throw the ball well and consistently.

Only then will Tebowmania become a reality in the NFL.

George Diaz can be reached at gdiaz@orlandosentinel.com. Follow him on Twitter @georgediaz