PITTSBURGH — Ben Roethlisberger’s left pectoral remains tender. His hip is apparently some unidentifiable shade of black and blue. His numbers aren’t great. His team’s record is even worse.

Yet the longtime Pittsburgh Steelers quarterback insists he’s not at the end. Not with 13 games still to play. Not while working behind an offensive line showing signs of progress. Not with an inner drive he insists is still very much alive a quarter of the way through his 18th season.

“I need to be better,” Roethlisberger said Wednesday. “I need to fight through and figure out how to make better decisions, how to make better throws, how to, you know, be a better football player. ... I’m not going to quit.”

Roethlisberger enters Sunday’s visit from Denver (3-1) as the NFL’s 27th-rated quarterback, his 78.9 rating just ahead of Miami’s Jacoby Brissett and just behind New England rookie Mac Jones. This is hardly the first time he’s gone through a slump. It is the first time, however, that he’s done it at age 39 while playing for an offense where he’s the oldest starter by more than a decade.

The friends he counted on for support for so long — from tackle Max Starks and tight end Heath Miller early in his career to center Maurkice Pouncey, tight end Vance McDonald and former offensive coordinator Randy Fichtner more recently — are gone.

Now he finds himself turning to defensive tackle Cam Heyward and outside linebacker T.J. Watt for support. Roethlisberger and Watt huddled at length following a 27-17 loss in Green Bay on Sunday that dropped Pittsburgh’s record to 1-3.

“There are guys that you can talk to and rely on, and you guys can come together and formulate a plan and see how it goes,” Roethlisberger said.

Maybe, but time is growing short. The Steelers are already two games behind everyone else in the AFC North and their best chance at turning things around needs to happen over their next five games, four of which will be played at Heinz Field.

Pittsburgh coach Mike Tomlin reiterated Tuesday that Roethlisberger is “absolutely” the best option at quarterback and that there are no plans to turn to backups Mason Rudolph and Dwayne Haskins. Roethlisberger has made it a point during the Steelers’ three-game losing streak to shoulder the blame for the offense’s shortcomings.

It’s a tact he’s taken regularly most of the past two decades when things have gotten sideways. He believes the accuracy issues he’s dealing with — particularly when it comes to his mechanics — are correctable, even if that means doing it with a throbbing hip that can make the act of throwing a football uncomfortable.

“I’ve got to find ways to be better with my lower body,” he said. “Going back and watching the game a few times, a lot of the throws that I missed were missed because my lower body wasn’t in sync over striding, not stepping towards my target. Things that you know mechanically that I know I can fix and need to fix.”

Wide receiver Diontae Johnson, who hauled in Roethlisberger’s 400th touchdown pass last weekend, brushed off the growing criticism of a player whose NFL career began while Johnson was in elementary school.

“(The naysayers are) on the outside looking in so they don’t know what we are doing each day and the hard work he puts and day in and day out,” Johnson said. “So I say we just got to shut out the noise and just focus on us and keep going and we’re going to bounce back.”

Having a completely overhauled offensive line starting to play with some consistency would help. The Steelers did run for a season-high 62 yards against the Packers, abandoning the run only because they fell behind.