Philadelphia matches up well against Arizona. They beat them in a tough 2013 game, and lost last year only because of a stupid defensive play.

The Eagles led 20-17 with 1:21 left. Arizona had the ball on their own 25. Might be a good time for a prevent defense, right? Instead, Cary Williams played tight on Williams, who predictably ran by him. Worse, safety Nate Allen bit on a double move, trying to be a hero by going for an interception on a short pass that was just a fake.

Brown flew by both for an easy touchdown. And no doubt, he’s one of the fastest receivers in the game. But half-decent coverage could have stopped the play or at least limited it to a long gain.

Since then, Allen signed with the Raiders as a free agent, and Cary Williams is out of football after the Seahawks cut him. The Eagles also replaced DBs coach John Lovett with Cory Undlin, who players rave about, and the unit as a whole is much better. So far, they’ve given up 44 passes of 20 yards or longer in 13 games. Last year, in 16, they surrendered 72.

But the secondary is still a work in progress. EJ Biggers is erratic at best. Nolan Carroll broke his ankle. Against Tampa Bay and Detroit, DC Bill Davis tried moving Malcolm Jenkins out of the nickel CB role back to a more traditional safety position. The Eagles gave up 45 points each to two of the league’s worst teams.

After they put Malcolm back in the slot and called up Ed Reynolds from the practice squad to play safety, the Birds beat New England and Buffalo, giving up only 28 and 20 points. And Reynolds clinched the Bills game with his late interception.

How well the Eagles handle John Brown tonight will be a good marker of their chances to win. Whether he faces Byron Maxwell or rookie Eric Rowe, Brown remains a deep threat who demands safety help to neutralize. The Eagles will need good coaching from Undlin, a smart defensive game plan and individual execution by Reynolds and Rowe, two green players, to have a chance at pulling off this upset.