NFL vice president of officiating Mike Pereira told The Boston Herald yesterday that the hit Sunday by Pittsburgh Steelers safety Ryan Clark that knocked out Patriots wide receiver Wes Welker, while nasty to watch, was within the rules, except for being somewhat late. Clark was penalized 15 yards on the play and many have accused him of taking a cheap shot at a defenseless receiver.

Pereira told the Herald's Ron Borges that despite a widespread perception, it is not illegal for a defensive player to leave his feet to make a hit, as Clark did on the Welker hit. Here's how Pereira explained the rules:

"It is a foul to hit with your helmet against a defenseless receiver. It is a foul to throw a forearm into the neck or head area of your opponent. I don't think either of those things happened. I'm not a fan of those high hits but if you do it with your shoulder you're OK."

As to the hit by Clark on Welker, Pereira said:

"He does actually lead with the shoulder on a high hit up in the area of the neck, but he left the helmet out of the contact. When you look at it and slow it down it probably was not an illegal hit. You might have to factor in that it was deflected early and does that make it become late. But the actual hit itself is probably OK."

Here's a video clip, see for yourself: