The final chapter in Michael Vick’s career might have been written Sunday, and by the least likely of sources in Steelers third-team quarterback Landry Jones.

Taking over for an injured Vick in the second half of a tight game with NFC West leader Arizona, Jones shocked everyone who had watched him the past two years by throwing for 168 yards and two TDs in Pittsburgh’s 25-13 win.

Now the Steelers would be hard-pressed to go back to the mostly ineffective Vick before Ben Roethlisberger returns, though a backup option might not be necessary based on how quickly Roethlisberger appears to be recovering from his Week 3 knee injury.

But if Pittsburgh needs a fill-in quarterback for this weekend’s visit to the struggling Chiefs, it will likely be Jones, not Vick (who has a “tiny tear” in his hamstring, via NFL Network).

Almost no one would have predicted that as recently as, oh, late Sunday afternoon. Jones had been woeful in practice and mediocre — at best — in copious amounts of preseason playing time, prompting the Steelers to desperately reach for the 35-year-old Vick off the scrap heap.

But Vick has been anemic in three starts, throwing for just 371 yards combined with a 79.8 passer rating and generally looking as done as he did while filling in for Geno Smith with the Jets last season.

Jones is big (6-foot-4, 225 pounds), has a strong arm and knows the Pittsburgh offense, something Vick has also struggled with essentially on the fly. The Steelers also have a dizzying array of big-play weapons, so Jones has an even better chance of succeeding for however long Roethlisberger needs to recover.

The 4-2 Steelers potentially stumbling into a quality substitute for Roethlisberger is also bad news for the Bengals, who are 6-0 but can no longer count on the possibility of running away with the AFC North.