Tennessee Titans quarterback Marcus Mariota added two more interceptions last week in Arizona. His 14 for the year is three less than NFL leader DeShone Kizer of the winless Cleveland Browns.

It had been festering for weeks, but the Tennessee Titans seemed to push the matter aside as they were squeezing out close wins against the NFL’s third-easiest schedule. “Winning ugly” is how it was seen through rose-colored glasses, with an 8-4 record as exhibit 1.

The Titans were finding ways to win, despite not playing their best, racking up victories against the Luck-less Colts, the Watson-less Texans and other dregs like the Bengals and winless Browns.

Not to worry, the optimists said while adjusting their tinted shades, the offense will come around.

But now, after Sunday’s desert debacle, the 8-5 Titans can no longer play off their passing bad as just a passing fad.

Nor can they ignore that Marcus Mariota has regressed to the point where they really don’t know what to expect from him on a game-to-game basis.

For a guy who seemed destined for superstardom toward the end of his second NFL season, Mariota now posts passing numbers more reminiscent of Vince Young or Jake Locker with just 10 touchdown passes and 14 interceptions.

His passer rating is now 76.9 for the year, placing him behind the likes of Colts fill-in Jacoby Brissett, Blake Bortles, Eli Manning and Jay Cutler.

He ranks 25th in the NFL among QBs with 300 or more passing attempts.

So, with three weeks left in the regular season and the Titans desperately needing to squeeze out wins to secure their first playoff berth in nine years, what can be done to fix Mariota and the offense?

Probably not much, until or unless Mariota regains his edge or the Titans find ways to play better around him.

Coach Mike Mularkey insists the Titans’ offensive woes are, to use his words, “very fixable.”

One thing is certain: Whatever is very fixable, there is certainly a lot of it that needs to be fixed.

“There’s things in life that aren’t (fixable); this is one that is,” Mularkey says. “We’ve got a good group, we’ve got a very good staff – very, very veteran staff that’s been in a lot of meetings and a lot of rooms, and a lot of games and been with a lot of players.

“Fortunately these guys trust what we’re going to do – again, looking it all over, how we can get better, everybody is. It’s being addressed.”

On Monday, Mularkey admitted that part of Mariota’s problems stem from his injuries, and he has a new one, a left knee sprain, that occurred during Sunday’s 12-7 loss to the Cardinals.

Mariota’s injury issues this season are well-documented and actually date back to last year, when he broke his right fibula on Christmas Eve against Jacksonville.

The offseason was spent rehabbing that injury, not readying to take the next step as a quarterback. And when Mariota admitted that many of his errant throws have been the result of poor technique and not setting his feet and stepping into his passes, the logical conclusion is that the leg injury is affecting his throws.

Mularkey, when asked if Mariota might be affected physically or even subconsciously, says maybe at first, but the in-season injuries (a strained hamstring and now a sprained knee) are to blame, as well.

“Maybe earlier in the year I’d say yes to that (leg injury affecting his throws),” Mularkey says. “I don’t know as much now as much as the injuries he’s sustained during this year affecting those, like this last one.”

While the quarterback shoulders much of the blame when an offense fails, Mariota is far from the only culprit here. The offensive line and the running game have been hot and cold. When it is cold, as it was Sunday, the passing game has not been good enough to offset it.

Why is that? Well, it goes far beyond just Mariota’s inaccuracies. There is mounting evidence that he does not trust most of his receivers.

Only Delanie Walker seems completely exempt from this mistrust, and therefore, you see the disproportionate number of targets that go his way.

Rookies Corey Davis and Taywan Taylor are still unpolished as route runners in the timing offense the Titans employ. Each had a bad mistake last Sunday, with Taylor not turning around soon enough to catch what could have been a big gain in the middle of the field, and Davis not getting on top in a crossing route, catching it a yard short of a first down.

Those types of mistakes have not been isolated incidents.

In Arizona, on the final play, the Titans apparently did not consider either of them a worthy option, instead lobbing an incomplete pass in the direction of full-time cornerback and part-time offensive contributor Adoree’ Jackson on fourth-and-10.

Which leads, of course, to questions about the play calling in general.

Certainly Mularkey and offensive coordinator Terry Robiskie have their share of culpability in seeing a productive offense in 2016 (11th overall) unraveled in the stretch run of 2017.

The Titans rank 21st out of 32 teams this week in total offense. Their passing offense ranks 27th.

Offensive coordinators are the easy scapegoat when teams don’t move the ball and score seven points against the NFL’s 24th-best defense (Arizona) or 12 points against the winless, hapless Browns.

There are times when the offense seems content to do just enough to get by, and Robiskie’s play sheet sometimes seems about as creative as the phone book.

Worse yet, once the Titans have a lead, the game plans often tend to become even more constricting and predictable.

A struggling quarterback, an inconsistent running game, unreliable pass catchers and sketchy play calling – add it up and the sum total is an underachieving Titans offense that might yet be “very fixable.”

But it must happen very soon.

Terry McCormick covers the Titans for TitanInsider.com