Count me as someone that's excited to see it.
If you recall, last year against the Baltimore Ravens, McKnight was used on a cornerback blitz. He pressured QB Joe Flacco into throwing a pick-six to LB David Harris. So what does that tell us? That McKnight won't be used as a traditional cornerback, if he's actually used at all. Instead, McKnight will likely be a decoy, a red herring. He could blitz with his 4.3 40 yard dash time, or he could simply draw the attention of QB Ben Roethlisberger and force him into doing something stupid. Let me explain...
With CB Darrelle Revis out, a very limited number of defensive backs, and a weakened Steelers offensive line, we should expect to see a lot more trickery this week by Rex Ryan. As OLB Bryan Thomas is out, I expect a lot more 4-3 looks with stunts, twists, and more zone coverage on the back end than we're used to. Attacking the offensive line is important because we simply can't afford to give Roethlisberger the time to throw, because our DBs are weaker than normal. With the weakening of our secondary, more zone coverages and man-zone combos will be necessary to cloud Roethlisberger's picture and make him hesitate before throwing, giving our line enough time to get there.
So there's the situation of McKnight blitzing, or if he stays in coverage, I can picture Roethlisberger trying to target him, with the defense in a deceptive look to make the strike more appealing, and then Ben realizing too late that the defense wasn't lined up how he thought it was, and blam-o, interception or sack. McKnight can be just a decoy to throw Roethlisberger another look or to confuse him. And in instances like that, where we can confuse Roethlisberger into throwing a pick, can you imagine what will happen if McKnight can get the ball in his hands? An actual running back on defense? That'd be a heck of a mismatch. McKnight is one of our biggest playmakers, and it's time to get the ball in his hands.
In short, Joe McKnight can, and should, be used as decoy on defense to make an already complex defense even harder to crack.