2017 might be the Steelers’ last chance with Le’Veon Bell and Ben Roethlisberger

Not until 2014, the 11th year of Ben Roethlisberger’s career, did the Steelers field a team that ranked higher in scoring offense than defense. Keeping other teams off the board has been the franchise’s ethos since the Steel Curtain of the 1970s, and the two teams Roethlisberger “led” to Super Bowls were, first off, defensive juggernauts. The Steelers’ formula had been to pair all-world defenses and good-enough offenses.

The script flipped three seasons ago. The offense jumped from 16th to seventh in scoring, and the defense continued a gradual decline to finish 18th. Things leveled off by last season, when both units were 10th, but the arc of the franchise was obvious. The Steelers had made three postseasons in a row because they could score.

2014 was the first year they had a full season of Le’Veon Bell. The ‘13 second-round pick has become his own kind of NFL running back, and he’s as efficient on the stat sheet as his running style is easy on the eyes.

The Steelers couldn’t strike a long-term deal with him before Monday’s league deadline. There’s a real chance this season is his last one by the three rivers. That means this could be the Steelers’ last shot to win a Super Bowl with this core.

Nineteen running backs have totaled 500 carries in the last three seasons, and Bell’s 4.8-yard carry average is .15 yards better than the next-best guys, LeSean McCoy and Mark Ingram. His 182 catches are the most among all running backs, and so are his 1,606 yards. He averages 7.1 yards per receiving target, making him a more efficient receiver than a whole lot of actual wide receivers. He’s close to a perfect player.

Bell is the best running back in the world, but his contractual future is very much in doubt. Even if the Steelers keep him, running backs don’t usually stay on top for long. Bell’s had a series of injuries in his first four pro seasons, including a groin ailment that required surgery this offseason. He’s an irreplaceable talent, but the odds that he’s both at the height of his powers and a Steeler in one year do not seem great.

We could run down the Steelers’ other running back options to evaluate what might happen if Bell declined or left town, but there’s no point. Losing this version of Le’Veon Bell would make any offense in the league miles less potent.

The quarterback said in January that he was considering retirement. This was not, apparently, a new thing. His coach said it had happened before:

Roethlisberger is under contract through 2019, and retirement would cause him to miss out on millions of dollars. But the Steelers might never again know with certainty that Roethlisberger is going to be there beyond a given season.

When Roethlisberger retires, the Steelers won’t contend for a seventh title until they’ve found a top-end replacement. Those don’t grow on trees. If his replacement walked into an offense that had a peak Bell, it’d be easier. But maybe he won’t.

And really, this should be a special season. Antonio Brown is still Antonio Brown. Bell will remain a star if healthy, and Roethlisberger should still be one of the handful of best quarterbacks anywhere. Home run-hitting receiver Martavis Bryant is conditionally un-suspended after missing last year, and a top-three offensive line is fully intact.

The defense got better last season and played well in the playoffs until it came up against Tom Brady. It’s a good enough unit to win a Super Bowl but probably only if it’s attached to a devastating offense. That’s what the Steelers have in this moment.

Bell is a singularly dominant running back and Roethlisberger a Hall of Fame quarterback. The Steelers will fall off considerably without either of them, and this is the last year both are guaranteed to play together. If it’s their swan song in the same backfield, the Steelers can only hope they’ll make beautiful music.