There was a time when the Patriots were the target, an evil empire that had been conquered. These days, Rex Ryan looks at the Patriots with envy more than anything else, especially when it comes to playing against Tom Brady.

Entering what most believe are his final days as the Jets’ head coach, Ryan guards his words, knowing they are being dissected for signs of resignation, anger, frustration and even sadness. What the embattled coach offered on Thursday was his theory on why the Pats have been so consistently good, having clinched their sixth straight AFC East title.

“Brady is a huge reason for it,” Ryan said. “It’s obviously a very successful system. But I think having that consistency at the quarterback position probably makes it a little easier than maybe other teams have gone through. I’ll just leave it at that.”

A few years ago, there would have been a touch of sarcasm in Ryan’s voice. Instead, there was respect for how Brady and the Patriots (11-3) have maintained a standard of excellence while the Jets are struggling through a 3-11 season. They meet Sunday at MetLife Stadium in what could be Ryan’s final game against his division rival.

“You know they’re the ones to beat,” Ryan said.

The Patriots are going to the playoffs again, while Ryan likely will be looking for work on another sideline or in a television booth. If he couldn’t fully understand how instability at quarterback can wreck a season and a franchise when he was a defensive coordinator, he knows now as a head coach.

If Mark Sanchez had improved in his first two seasons when he led the Jets to back-to-back AFC Championship games, and became the franchise quarterback he was drafted to be, Ryan wouldn’t be getting fired. If Geno Smith were not the turnover machine he has been over his first two seasons, then maybe the Jets and Patriots would be playing for something on Sunday. Heck, if even Michael Vick had given the team some kind of spark, maybe Ryan would have survived another year. Instead, the Jets will be searching for a new head coach largely because they still are searching for a quarterback.

Not all of it is Ryan’s fault. He made a poor choice in hiring Tony Sparano as offensive coordinator in 2012 to replace Brian Schottenheimer. Sparano had signed a three-year deal but was fired after one season in which the Jets’ offense ranked 30th out of 32 teams. But then Ryan hired Marty Mornhinweg, a proven offensive mind who had success calling offenses for the 49ers and Eagles. Ryan has left the offense and the development of Smith in Mornhinweg’s capable hands, but that hasn’t worked either.

The common thinking is Smith was asked to do too much too soon. The instant success that Colts quarterback Andrew Luck and Seattle Super Bowl winner Russell Wilson have enjoyed has made everyone impatient with the development of quarterbacks.

“Most guys, it takes a little bit of time to develop them into where you can have this vast playbook,” Ryan said.

The Jets’ situation has regressed to the point where it’s unclear whether Ryan and Mornhinweg are on the same page. Mornhinweg sounded on Thursday like he would have preferred to have passed the ball more, but was pressed to call more of a running attack because of “the way we’re built and trying to take care of the ball a little bit better.” Yet he countered with, “Certainly, the passing game, you’ve got to get that going at some point to win on a consistent basis.”

As coaches and teachers, neither Ryan nor Mornhinweg has given up on Smith, understanding there are no other options at this point.

“Geno has played some fine games, including last week,” Mornhinweg said of the Jets’ 16-11 victory over the Titans. “His challenge is to play at a high level on a consistent basis.”

It all would be different if the Jets could have developed a quarterback close to a Tom Brady. I’ll just leave it at that.