THE JETS surrendered two picks and three players to trade up and take Mark Sanchez fifth overall in 2009. He was the quarterback when the Jets went to the AFC title game his first two seasons. He earned a clever nickname.

But the value of "The Sanchise" plunged in 2011 and 2012. He had a chance to rebuild his brand's equity this season as Nick Foles' replacement.

That equity spiked early, but the specter of two tough, meaningful games loomed as better gauges of Sanchez's true value.

His equity plunged the past 2 weeks.

The Sanchise needs to play very well Saturday in Washington to recoup his recent, massive losses and make himself a viable product as his career marches on.

"I'm not worried about what kind of message I'm sending externally," he said. "As far as me, and my stock, I don't care. That doesn't matter."

Of course it does.

At issue: Is Sanchez healthy? Can he recognize and defeat blitzes? Are his fundamentals crumbling? After five games, did teams catch up with him in Chip Kelly's scheme?

The answers: maybe; sometimes; you would hope not; and, probably.

Circumstances that seem obvious in December often get denied until January.

In his first five games, Sanchez completed 63.4 percent of his passes, compiled an 89.3 passer rating and helped the team go 4-1.

In his last two games, losses to visiting Seattle and Dallas, he dropped to 56.3 percent with a 67.0 rating and was the worst player . . . at least, he was the worst player on offense.

Offensive coordinator Pat Shurmur yesterday testified that Sanchez's issues essentially boil down to flawed fundamentals, while Sanchez believes the issue lies in the guys who seek to hasten his demise. Seattle has the best defense in the NFL and Dallas faced the Birds twice in three games.

"We played against a couple of good defenses - a division opponent, last week, who knows a lot of our stuff," Sanchez said. "We're going to face a similar challenge this week."

The whole team is going to face the challenge, Sanchez said. He will have to be more daring, be willing to throw receivers open, but it's not only him; it's receivers who have run imprecise routes and have dropped passes.

"We're going to have to be sharp, going to have to be accurate," Sanchez said. "Make those tough catches. Going to have to anticipate."

When the Eagles play at Washington on Saturday, as Sanchez noted, they will face another division foe for the second time this season. The Birds insist he is as fit as ever.

Shurmur dismissed the possibility that Sanchez, who missed last season due to shoulder surgery, is suffering arm fatigue. A dead arm might explain why Sanchez has been startlingly inaccurate the past two starts.

"It feels fine," he said.

He keeps missing high and right, the bugaboo that has dogged him his entire career, said Shurmur. This has more to do with shoulder level than with shoulder strength, said Shurmur.

"Typically when Mark misses a throw, it's high," Shurmur said. "It's a matter of going back to the fundamentals, keeping your front shoulder down, all the things that we know."

Sanchez agreed.

"It's something you've got to go back to all the time . . . especially as the season goes on, especially down the stretch," Sanchez said. "Two hands on the ball, stepping up in the pocket, finishing your throws. That preparation and training will set you free on game day."

Even Jack Nicklaus used a swing coach to ensure he kept finding fairways, but it seems unusual that Sanchez could become fundamentally unhinged five games into his sixth NFL season.

Maybe when the Eagles are watching the playoffs next month, they will admit that it was a tired shoulder, not flawed mechanics, that sabotaged them in December.

Then again, maybe Sanchez's slump has more to do with the competition.

Against the Seahawks, Sanchez was, at the very least, cautious; at worst, overcautious. The Eagles opened the game with two plays designed to find tight end Brent Celek in timing routes over the middle. Sanchez pulled down the first throw and threw late on the second.

Has he become gun-shy?

"No, I haven't seen him be gun-shy," Shurmur said. "I don't think I'm seeing him pull the ball down and not throw it deep, when it's there."

"No way. Not at all," Sanchez said.

Sanchez's biggest miss against the Seahawks, of course, was a deep third-down pass to 250-pound tight end Zach Ertz, who leaped but failed to catch it.

There was no need for the pass to be so high.

Neither Dallas nor Seattle blitzes much, but they effectively blitzed Sanchez. Shurmur insisted that Sanchez was not having trouble recognizing blitzes.

That means either that the Eagles have failed to pick them up; that Sanchez is failing to beat the blitzes; that Sanchez's teammates are not executing their roles in defeating the blitz; or, all of the above.

Or, to hear Shurmur and Sanchez tell it, none of the above.

"I don't think that's really been our problem. I think we've identified it well," said Sanchez.

He was sacked nine times in his first five games. He has been sacked seven times in the past two. More could come Saturday. Washington defensive coordinator Jim Haslett blitzes as often as he blinks, and the woeful Redskins are playing with house money.

The Seahawks connected with a blitz by nickel corner Marcus Burley from Sanchez's left when Sanchez appeared to miss the outlet receiver. There appeared to be no "hot" receiver on a later blitz, either.

He threw late to Riley Cooper, high and behind Josh Huff, overthrew Ertz for an interception late in the third quarter, was surprised by a blitz and took a sack on his first play in the fourth, and overthrew Celek to squelch that same drive.

Missing blitzes, missing open receivers, not throwing receivers open, throwing late - a quarterback might overcome any one of these issues and still win.

A quarterback frequently failing in all of these areas makes winning impossible. It took the Jets 5 years to realize this.

The Jets sold the farm to draft him. In 2012, the Jets gave him $20.5 million in guaranteed money to stay through 2013. They still opted to replace him with Geno Smith and Michael Vick.

Kelly repeatedly insisted that he never watched tape of The Sanchise's performances as a Jet.

He should have.

On Twitter: @inkstainedretch

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