The Steelers offense is stacked. So why has it been so underwhelming?

The Steelers rolled into Week 5 as a 7.5-point favorite over the Jaguars. They limped off the field after a 21-point loss. The only touchdowns their offense saw were when Jacksonville defenders rumbled in the opposite direction to cap off pick-six interceptions.

Pittsburgh may have had the worst performance in a week full of awful football, leaving a home crowd baffled and Ben Roethlisberger questioning his own talent — albeit sarcastically.

The veteran quarterback, 35 years old but dragging approximately 1,000 bruising tackles behind him as he trudges deeper into a Hall of Fame career, is in the midst of the most mediocre football of his life. Sunday’s loss marked the first time in 11 games he’d thrown for more than 300 yards. He negated any kind of goodwill from that stat by slinging five interceptions.

Roethlisberger is the first quarterback in league history to throw more than 50 passes with no touchdowns and five interceptions in a game. Even so, this loss can’t be placed entirely at his feet. Two of his picks were the result of tipped balls. A third came after his intended target slipped and crashed to the turf while his pass was already in the air.

It’s reasonable to write one bad game off as a lapse, but the Steelers have failed to find their top gear throughout the early stages of the 2017 season. The club ranks 19th in the league in points per game, 23rd in yards per play, 13th in passing offense, and a baffling 24th in rushing yards per game.

And this is a team that employs All-Pro building blocks Le’Veon Bell and Antonio Brown.

Brown, on pace for a 1,700-yard receiving season, isn’t the problem. Bell might be. Bell lobbied for a long-term contract with the Steelers before signing a one-year franchise player contract tender for $12.12 million in September. His holdout cost him much of training camp, and he’s so far been ineffective to kick off his contract season.

Some of that can be attributed to a schedule that’s featured three top-10 rushing defenses, but that excuse umbrella doesn’t cover all of Bell’s struggles. Jacksonville, the league’s worst rushing defense, had allowed opposing tailbacks to rush for 5.7 yards per carry in its first four games. On Sunday, Bell had 15 touches for 47 yards. While he broke away for 144 yards against Baltimore and its 20th-ranked rush D, he needed 35 carries to get there.

Bell, who wanted to be paid like a No. 1 running back and No. 2 wide receiver, currently ranks second on the team in receptions but just fifth in receiving yards. Roethlisberger is still targeting him on screens and checkdown plays, but he hasn’t displayed the elusive qualities that allowed him to catch a pass near the line of scrimmage and turn it upfield for a first down.

Bell wants more carries — a strategy that paid off against Baltimore. He got only 15 Sunday in a game in which Pittsburgh played from behind for 42 minutes. The question now is whether he’ll return to form and justify the kind of role he had in All-Pro seasons in 2014 and 2016.

He isn’t the only expected Steeler contributor to struggle early in 2017. Martavis Bryant’s return from suspension has given the team an additional deep threat, but he’s caught fewer than 50 percent of his targets and is averaging just three catches per game. Rookie JuJu Smith-Schuster hasn’t been utilized much as a wideout (12 receptions) or on special teams. Vance McDonald, added to the roster at the end of the preseason to bolster depth at tight end, is 0-of-4 on targets this fall.

Pittsburgh’s struggles are another strong point to support the argument the 2017 AFC playoff race is the Chiefs and then everyone else. With Kansas City carving up opponents — it’s averaged 36 points per game against conference foes — the only way to stop the new AFC favorites may be in a shootout. The Steelers looked up to the task in the preseason, but after going without a touchdown in Week 5, confidence for last season’s conference finalists is dipping.

That makes Sunday afternoon’s showdown in Kansas City an important litmus test for each team. The Pittsburgh defense has allowed 19 or more points just once this season when a gassed unit let Jordan Howard slip into the end zone for a Bears overtime victory. Kansas City, scoring nearly 33 points per game, is the NFL’s top scoring offense. Something has to give, and odds are it won’t be the rejuvenated Chiefs’ ground-and-air attack.

That means the Steelers will have to respond in kind. Roethlisberger and Bell will have to shake off their slow starts to 2017 to get there.

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