PITTSBURGH -- Lost in the drama of the last-second fight with the Cleveland Browns on Thursday was another ugly reality: The Pittsburgh Steelers' offense is in serious trouble.

After a performance against the Miami Dolphins in Week 8 in which it looked like everything was starting to click -- wide receiver JuJu Smith-Schuster and running back James Conner each hit 100 yards for the first time this season -- the Steelers' offense has declined in the past three games to averaging marks near the bottom of the league in most offensive categories.

Pittsburgh’s 283.5 yards per game and 4.84 yards per play rank 28th and 27th, respectively. The team’s total QBR through 10 games is 36.4, good for 28th in the league, and both the 80.7 rushing yards per game and 202.8 passing yards per game rank 27th in the NFL.

It’s a far cry from the offense of the past couple of seasons that routinely put up stats in the top 10.

The solution might be rather complicated.

“That’s kind of like asking someone what the answer is in a big problem set in physics, and you just say, ‘I want to know the answer,’” offensive lineman Alejandro Villanueva said. “Well, there’s a lot more that goes into the answer.”

Playing against a Miami defense that allowed 414 yards per game covered some of the Steelers’ offensive deficiencies, including an inexperienced quarterback, shoddy depth and no clear No. 2 receiver. But the past three weeks, injuries to the Steelers’ top playmakers have exacerbated the team’s offensive issues.

With the offseason departures of receiver Antonio Brown and running back Le'Veon Bell, the Steelers lacked depth at their skill positions entering the season. Injuries to Conner, Smith-Schuster and receiver Diontae Johnson have forced the team to cobble together a backfield and wide receiving corps with elevated practice-squad players. Since Thursday’s game, the Steelers signed running back Kerrith Whyte and wide receiver Deon Cain to the active roster from the Chicago Bears' and Indianapolis Colts' practice squads, respectively. They also added two wide receivers and a running back to the practice squad.

“Never seen it,” Villanueva said of the amount of injuries. “... At the end of the day, it happens. It happens to other teams. We’ve been watching from afar. Sometimes it happens to you, and you have to make the best out of it.

“... You always have to make sure that you’re not the one that’s getting caught less than ready and making excuses of why are things not working out the way they should.”

Conner was injured in the final two minutes of that win over the Dolphins, and initially, the Steelers considered making a trade-deadline move to acquire Bell, a source told ESPN’s Adam Schefter. But once Conner’s injury was determined to not be as serious as initially feared, the Steelers opted to fill Conner’s void the next two weeks with a slew of bottom-of-the-roster transactions. That’s what led to former practice-squad backs Tony Brooks-James and Trey Edmunds taking on larger roles against the Colts and the Los Angeles Rams.

But after averaging 5.4 yards per carry against the Dolphins, the Steelers managed just 3.6 against the Colts and 1.6 against the Rams. Thanks to strong performances by the defense, the Steelers won both of those games.

Conner returned Thursday, but the run game didn’t get any better. Playing through shoulder pain, Conner wasn’t able to channel the reckless running style that has made him so effective throughout this career.

“I could tell he wasn’t fully 100 [percent],” fellow back Jaylen Samuels said. “... He wanted to be out there with us to make plays, help us win. I can’t blame him for that. He tried and got hurt a little bit, early first quarter. Said he couldn’t go back out there.”

Conner finished with 10 yards on five carries, and a patchwork group managed just 41 yards on 10 carries in his absence.

Quarterback Mason Rudolph played his worst game as a Steeler, with four interceptions and 221 passing yards. Although many of his passes were off-target, his dismal numbers were also a product of injuries to the wide receivers.

The Steelers finished Thursday's loss without their top-two receivers after both Smith-Schuster and Johnson exited early with concussions. Smith-Schuster also sustained a knee injury, a source told Schefter, which puts his status for Sunday’s game in Cincinnati in doubt.

With Johnson and Smith-Schuster sidelined Thursday and wide receiver Ryan Switzer placed on injured reserve before the game, the Steelers turned to a trio of unproven receivers in James Washington, Johnny Holton and Tevin Jones. Washington is the lone drafted player of the group and the only one who had a catch with the team before Thursday.

As a group, they combined for 91 yards on six catches. Holton had one reception on seven targets.

All of those factors saw the Steelers average 3.7 yards per play and go 2-of-14 on third and fourth downs.

“We just got to execute,” Samuels said. “When they send pressure on third down, we just got to pick it up with our pass protection. Guys, receivers got to make tough catches. Mason got to make great throws. Everybody’s got to execute. That’s the main thing.”